这里是一个片段，但正如其他人所说，更喜欢css并在script标签中创建一个侦听器来更改样式，如第二个片段或第三个片段（如果脚本在head标签中）。

<div id = "anotherDiv" style="width: 200px; height: 100px; background-color:#995500;"></div>
    <div onmouseover="document.getElementById('anotherDiv').style.backgroundImage='url(https://dummyimage.com/200x100/666666/fff)'" style="cursor: pointer;">mouse over to change the background and use an image.
    </div>

第二个片段：

let mOverDiv = document.getElementById("mOverDiv");
        let anotherDiv = document.getElementById("anotherDiv");
        mOverDiv.addEventListener("mouseover", changeStyle);
        function changeStyle(e){
            anotherDiv.style.backgroundImage='url(https://dummyimage.com/200x100/666666/fff)';
        }

#anotherDiv{
            width:200px;
            height:100px;
            background-color:#996600;
        }
        #mOverDiv{
            cursor:pointer;
        }

<div id = "anotherDiv"></div>
    <div id = "mOverDiv">text in div</div>

如果您的脚本是在head部分中声明的，请使用第三个代码段。因此，您需要等待内容加载完毕，然后才能分配'divs'标记和侦听器：

let mOverDiv;
        let anotherDiv;
        document.addEventListener("DOMContentLoaded",addListener);
        function addListener(e){
            mOverDiv = mOverDiv = document.getElementById("mOverDiv");
            anotherDiv = document.getElementById("anotherDiv");
            mOverDiv.addEventListener("mouseover", changeStyle);
        }
        function changeStyle(e){
            anotherDiv.style.backgroundImage='url(https://dummyimage.com/200x100/666666/fff)';
        }

#anotherDiv{
            width:200px;
            height:100px;
            background-color:#996600;
        }
        #mOverDiv{
            cursor:pointer;
        }

<div id = "anotherDiv"></div>
    <div id = "mOverDiv">text in div</div>

您不需要为url（）添加引号，请执行以下操作

<div onmouseover="document.getElementById('anotherDiv').style.backgroundImage = 'url(https://www.test.com/image.jpg)'"></div>