1.用到下面的插件

cordova-plugin-file github

2.代码

    window.resolveLocalFileSystemURL(cordova.file.applicationDirectory, function (dirEntry) {  
        console.log('file system open: ' + dirEntry.name);  
        console.log(dirEntry); 
        console.log(dirEntry.nativeURL); 
        dirEntry.getFile("www/test.bin",{create : false},function(fileEntry){
            console.log(fileEntry)
            fileEntry.file(function (file) {
                var reader = new FileReader();
                reader.onloadend = function() {
                    console.log("Successful file read: " + this.result);
                    console.log(this.result)
                    firmware = this.result
                };
        
                reader.readAsArrayBuffer(file);
            })
        },function(error){
            console.log(error)
        })
    }, function(){});   

3.打印截图

4.下面的博客记录了我解决问题的过程

cordova js(javascript)读取本地文件（将本地的bin文件转成字节数组）