试试这个解决方案，我想应该可以：https://www.tutorialspoint.com/how-to-resize-the-background-image-to-window-size-in-tkinter

这不是一个简单的任务。如果你想有一个可调整大小的图像，那么你需要使用PIL包。此外，还需要一个进一步的方法来动态地调整图像。当然，如果窗口大小总是保持不变，解决方案可以实现如下：

self.image = self.img_copy.resize((new_width, new_height))
#resize is included in the PIL.Image module

要动态调整背景图片的大小，代码可能如下所示：

import tkinter as tk
from tkinter import ttk
from scipy import misc,datasets
from PIL import Image, ImageTk


class MongoDBGUI:
    def __init__(self, master):
        self.master = master
        self.master.title("MongoDB Cloud Search and Display")
        self.master.geometry("1000x400")

        self.image = Image.open("background.png")
        self.background_image = ImageTk.PhotoImage(self.image)
        self.img_copy = self.image.copy()
        self.background_label = tk.Label(self.master, image=self.background_image)
        self.background_label.place(relwidth=1, relheight=1)

        self.label = tk.Label(self.master, text="Enter search criteria:")
        self.label.pack()

        self.entry = tk.Entry(self.master)
        self.entry.pack()

        self.search_button = tk.Button(self.master, text="Search", command=self.search)
        self.search_button.pack()

        self.tree = ttk.Treeview(self.master)
        self.tree.pack()
        self.tree["columns"] = ("transcript", "audio_file", "audio")
        self.tree.column("transcript", width=400, anchor="center")
        self.tree.column("audio_file", width=150, anchor="center")
        self.tree.column("audio", width=50, anchor="center")
        self.tree.heading("transcript", text="Transcript")
        self.tree.heading("audio_file", text="Audio File Number")
        self.tree.heading("audio", text="Audio")
        self.background_label.bind('<Configure>', self._resize_image)

    def _resize_image(self,event):

        new_width = event.width
        new_height = event.height

        self.image = self.img_copy.resize((new_width, new_height))

        self.background_image = ImageTk.PhotoImage(self.image)
        self.background_label.configure(image =  self.background_image)

master=tk.Tk()
test=MongoDBGUI(master)
master.mainloop()