to crown it all idiom UK informal
最糟糕的是
used to say that something is the worst thing to happen in a series of unpleasant events
I had lost my ticket, was soaked to the skin, and, to crown it all, discovered that my purse had been stolen. 我把票弄丢了，又被淋得浑身湿透，最糟糕的是，我发现我的钱包被偷了。