Hello,
I have different sketch file,
can i combining different sketch into one sketch ?
Hello @HsuYuCHe, welcome to the Forum!
You can combine layers or artboards from different files by copying and pasting from one file to another.
If you are working with libraries and you want to merge two files into a single library file, plugins can help as well, and I’ll be more than happy to provide further details.
One more handy tip is that if you have two Sketch windows open at a time, you can actually drag a page from one to the other to copy it over as well 
While you can even do this with multiple pages, I would recommend that If it’s a particularly large/heavy document then do them one by one.
Otherwise, as @dfmedrano mentioned you can copy/paste artboards as well