我知道这是一个陈旧的线程（16个月前），但它是谷歌的顶部结果，这意味着它得到了很多的意见。我认为这可能会有利于其他人...
Mack是对的，使用Get-Hash有一个更漂亮更简单的解决方案。你可以通过比较Hash来简单地比较IF语句中的Hash。

# Get the file hashes
$hashSrc = Get-FileHash $file -Algorithm "SHA256"
$hashDest = Get-FileHash $file2 -Algorithm "SHA256"

# Compare the hashes & note this in the log
If ($hashSrc.Hash -ne $hashDest.Hash)
{
  Add-Content -Path $cLogFile -Value " Source File Hash: $hashSrc does not 
  equal Existing Destination File Hash: $hashDest the files are NOT EQUAL."
}

一定有更漂亮的解决方案，但这就是我最终使用的。

# Get the file hashes
$hashsourcefile = Get-Hash $file -Algorithm "SHA256"
$hashdestfile = Get-Hash $file2 -Algorithm "SHA256"

# Compare the hashes
Compare-Object -Referenceobject $hashsourcefile -Differenceobject $hashdestfile | % { If ($_.Sideindicator -ne " ==") {$diff+=1} }                  

# The Hashes are different. Note this in the log
if ($diff -ne 0)
{
    Add-Content -Path $cLogFile -Value " Source File Hash: $hashsourcefile does not equal 
    Existing Destination File Hash: $hashdestfile the files are NOT EQUAL."
}

因此，这里有一个未经测试的解决方案，至少应该让你走在正确的方向：

#first make a hash table of the files in folder 1 where the keys are the file hashes and the values are the file objects
$folder1Files = @{}
foreach($file in $cDestPath){
    $hash = Get-Hash $file
    if($folder1Files.ContainsKey($hash)){
        # A hash collision isn't likely but not unheard of. You should probably just handle them manually
        'There was a hash collision for {0} and {1} in folder {2}' -f $file.Name, $folder1Files[$hash].Name, $cDestPath
    }else{
        $folder1Files[$hash] = $file
    }
}
# Now do the same thing for folder 2
$folder2Files = @{}
foreach($file in $cDlPath){
    $hash = Get-Hash $file
    if($folder2Files.ContainsKey($hash)){
        # A hash collision isn't likely but not unheard of. You should probably just handle them manually
        'There was a hash collision for {0} and {1} in folder {2}' -f $file.Name, $folder1Files[$hash].Name, $cDlPath
    }else{
        $folder2Files[$hash] = $file
    }
}
# Actually you should really take those two bits and generalize them to a function that you pass a folder to and it returns the hash table.

# Now that you have your two sets of file hashes, use Compare-Object to find the diffs
$comparison = Compare-Object $folder1Files.Keys $folder2Files.Keys
foreach($diff in $comparison){
    if($diff.SideIndicator -eq '<='){
        'File {0} in folder {1} is different from any file in the other folder' -f $folder1Files[$diff.InputObject], $cDestPath
    }else{
        'File {0} in folder {1} is different from any file in the other folder' -f $folder2Files[$diff.InputObject], $cDLPath
    }
}

就像我说的，我现在没有时间测试和解决任何bug，但至少这应该作为我如何解决这个问题的伪代码。

这对我来说非常有效-比较源代码的两个分支。计数为1的组在另一个分支中没有MD5哈希孪生。例如：

$paths = 'c:\proj\trunk\source','c:\proj\branches\release\1.0\source'
ls $paths -r *.cs | Where {$_.PSPath -notmatch '\\obj\\'} | 
    Get-Hash | Select Path,HashString | Group HashString | 
    Where {$_.Count -eq 1} | Sort Count -desc | Format-List

使用MD5散列进行递归目录文件内容比较

我写了这个纯PowerShell v3+（没有相依性）递归目录diff，透过MD5杂凑比较内容。使用-ExportSummary [summary/path]参数，它会汇出一组左、右手目录的csv diff，以及diff的摘要档案。否则会在stdout上给予标准的比较对象diff结果。您可以将rdiff.ps1档案放到您的路径中，然后使用Set-ExecutionPolicy RemoteSigned、或者将内容直接复制到脚本中。

USAGE: rdiff path/to/left,path/to/right [-s path/to/summary/dir]

这是gist。推荐使用gist版本，因为它可能在下面的版本上添加了额外的功能。

#########################################################################
### USAGE: rdiff path/to/left,path/to/right [-s path/to/summary/dir]  ###
### ADD LOCATION OF THIS SCRIPT TO PATH                               ###
#########################################################################
[CmdletBinding()]
param (
  [parameter(HelpMessage="Stores the execution working directory.")]
  [string]$ExecutionDirectory=$PWD,

  [parameter(Position=0,HelpMessage="Compare two directories recursively for differences.")]
  [alias("c")]
  [string[]]$Compare,

  [parameter(HelpMessage="Export a summary to path.")]
  [alias("s")]
  [string]$ExportSummary
)

### FUNCTION DEFINITIONS ###

# SETS WORKING DIRECTORY FOR .NET #
function SetWorkDir($PathName, $TestPath) {
  $AbsPath = NormalizePath $PathName $TestPath
  Set-Location $AbsPath
  [System.IO.Directory]::SetCurrentDirectory($AbsPath)
}

# RESTORES THE EXECUTION WORKING DIRECTORY AND EXITS #
function SafeExit() {
  SetWorkDir /path/to/execution/directory $ExecutionDirectory
  Exit
}

function Print {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Message to print.")]
    [string]$Message,

    [parameter(HelpMessage="Specifies a success.")]
    [alias("s")]
    [switch]$SuccessFlag,

    [parameter(HelpMessage="Specifies a warning.")]
    [alias("w")]
    [switch]$WarningFlag,

    [parameter(HelpMessage="Specifies an error.")]
    [alias("e")]
    [switch]$ErrorFlag,

    [parameter(HelpMessage="Specifies a fatal error.")]
    [alias("f")]
    [switch]$FatalFlag,

    [parameter(HelpMessage="Specifies a info message.")]
    [alias("i")]
    [switch]$InfoFlag = !$SuccessFlag -and !$WarningFlag -and !$ErrorFlag -and !$FatalFlag,

    [parameter(HelpMessage="Specifies blank lines to print before.")]
    [alias("b")]
    [int]$LinesBefore=0,

    [parameter(HelpMessage="Specifies blank lines to print after.")]
    [alias("a")]
    [int]$LinesAfter=0,

    [parameter(HelpMessage="Specifies if program should exit.")]
    [alias("x")]
    [switch]$ExitAfter
  )
  PROCESS {
    if($LinesBefore -ne 0) {
      foreach($i in 0..$LinesBefore) { Write-Host "" }
    }
    if($InfoFlag) { Write-Host "$Message" }
    if($SuccessFlag) { Write-Host "$Message" -ForegroundColor "Green" }
    if($WarningFlag) { Write-Host "$Message" -ForegroundColor "Orange" }
    if($ErrorFlag) { Write-Host "$Message" -ForegroundColor "Red" }
    if($FatalFlag) { Write-Host "$Message" -ForegroundColor "Red" -BackgroundColor "Black" }
    if($LinesAfter -ne 0) {
      foreach($i in 0..$LinesAfter) { Write-Host "" }
    }
    if($ExitAfter) { SafeExit }
  }
}

# VALIDATES STRING MIGHT BE A PATH #
function ValidatePath($PathName, $TestPath) {
  If([string]::IsNullOrWhiteSpace($TestPath)) {
    Print -x -f "$PathName is not a path"
  }
}

# NORMALIZES RELATIVE OR ABSOLUTE PATH TO ABSOLUTE PATH #
function NormalizePath($PathName, $TestPath) {
  ValidatePath "$PathName" "$TestPath"
  $TestPath = [System.IO.Path]::Combine((pwd).Path, $TestPath)
  $NormalizedPath = [System.IO.Path]::GetFullPath($TestPath)
  return $NormalizedPath
}

# VALIDATES STRING MIGHT BE A PATH AND RETURNS ABSOLUTE PATH #
function ResolvePath($PathName, $TestPath) {
  ValidatePath "$PathName" "$TestPath"
  $ResolvedPath = NormalizePath $PathName $TestPath
  return $ResolvedPath
}

# VALIDATES STRING RESOLVES TO A PATH AND RETURNS ABSOLUTE PATH #
function RequirePath($PathName, $TestPath, $PathType) {
  ValidatePath $PathName $TestPath
  If(!(Test-Path $TestPath -PathType $PathType)) {
    Print -x -f "$PathName ($TestPath) does not exist as a $PathType"
  }
  $ResolvedPath = Resolve-Path $TestPath
  return $ResolvedPath
}

# Like mkdir -p -> creates a directory recursively if it doesn't exist #
function MakeDirP {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Path create.")]
    [string]$Path
  )
  PROCESS {
    New-Item -path $Path -itemtype Directory -force | Out-Null
  }
}

# GETS ALL FILES IN A PATH RECURSIVELY #
function GetFiles {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Path to get files for.")]
    [string]$Path
  )
  PROCESS {
    ls $Path -r | where { !$_.PSIsContainer }
  }
}

# GETS ALL FILES WITH CALCULATED HASH PROPERTY RELATIVE TO A ROOT DIRECTORY RECURSIVELY #
# RETURNS LIST OF @{RelativePath, Hash, FullName}
function GetFilesWithHash {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Path to get directories for.")]
    [string]$Path,

    [parameter(HelpMessage="The hash algorithm to use.")]
    [string]$Algorithm="MD5"
  )
  PROCESS {
    $OriginalPath = $PWD
    SetWorkDir path/to/diff $Path
    GetFiles $Path | select @{N="RelativePath";E={$_.FullName | Resolve-Path -Relative}},
                            @{N="Hash";E={(Get-FileHash $_.FullName -Algorithm $Algorithm | select Hash).Hash}},
                            FullName
    SetWorkDir path/to/original $OriginalPath
  }
}

# COMPARE TWO DIRECTORIES RECURSIVELY #
# RETURNS LIST OF @{RelativePath, Hash, FullName}
function DiffDirectories {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Directory to compare left.")]
    [alias("l")]
    [string]$LeftPath,

    [parameter(Mandatory=$TRUE,Position=1,HelpMessage="Directory to compare right.")]
    [alias("r")]
    [string]$RightPath
  )
  PROCESS {
    $LeftHash = GetFilesWithHash $LeftPath
    $RightHash = GetFilesWithHash $RightPath
    diff -ReferenceObject $LeftHash -DifferenceObject $RightHash -Property RelativePath,Hash
  }
}

### END FUNCTION DEFINITIONS ###

### PROGRAM LOGIC ###

if($Compare.length -ne 2) {
  Print -x "Compare requires passing exactly 2 path parameters separated by comma, you passed $($Compare.length)." -f
}
Print "Comparing $($Compare[0]) to $($Compare[1])..." -a 1
$LeftPath   = RequirePath path/to/left $Compare[0] container
$RightPath  = RequirePath path/to/right $Compare[1] container
$Diff       = DiffDirectories $LeftPath $RightPath
$LeftDiff   = $Diff | where {$_.SideIndicator -eq "<="} | select RelativePath,Hash
$RightDiff   = $Diff | where {$_.SideIndicator -eq "=>"} | select RelativePath,Hash
if($ExportSummary) {
  $ExportSummary = ResolvePath path/to/summary/dir $ExportSummary
  MakeDirP $ExportSummary
  $SummaryPath = Join-Path $ExportSummary summary.txt
  $LeftCsvPath = Join-Path $ExportSummary left.csv
  $RightCsvPath = Join-Path $ExportSummary right.csv

  $LeftMeasure = $LeftDiff | measure
  $RightMeasure = $RightDiff | measure

  "== DIFF SUMMARY ==" > $SummaryPath
  "" >> $SummaryPath
  "-- DIRECTORIES --" >> $SummaryPath
  "`tLEFT -> $LeftPath" >> $SummaryPath
  "`tRIGHT -> $RightPath" >> $SummaryPath
  "" >> $SummaryPath
  "-- DIFF COUNT --" >> $SummaryPath
  "`tLEFT -> $($LeftMeasure.Count)" >> $SummaryPath
  "`tRIGHT -> $($RightMeasure.Count)" >> $SummaryPath
  "" >> $SummaryPath
  $Diff | Format-Table >> $SummaryPath

  $LeftDiff | Export-Csv $LeftCsvPath -f
  $RightDiff | Export-Csv $RightCsvPath -f
}
$Diff
SafeExit

使用Powershell的简单方法
SHA1 SHA256 SHA384 SHA512 MD5接口模块

$x = 'hash value from the place you download'
$y = get-fileHash <your file local name > -algorithm MD5
$y.hash -eq $x // compare the hash values