可試：

var indexes = db.user.getIndexes();

indexes.forEach(function(index){
    delete index.v;
    delete index.ns;

    var options = [];
    for (var option in index) {
        if (option != 'key') {
            options.push(index['option']);
        }
    }
   db.usertest.createIndex(index.key, options);
});