After booking a hotel with Ctrip, it sent a message to confirm. Do I need to reply? thank you

If you chose to confirm by SMS at that time, she sent a message just to check your information. If your information is correct, you don't have to reply. If the information and check-in time are wrong, you should call her and tell her. I travel a lot, so I often use Ctrip to book hotels, but I always ask her to confirm by phone, which is more clear.

I hope my personal experience will help you.