Baidu knows how to cancel a mobile phone that receives an SMS notification.

By default, that mobile phone is your secret mobile phone bound by Baidu. If you don't want to receive this reminder message with an answer, you can remove the tick on the picture before asking questions, so Baidu won't send you a message.

If you want to unbind, please go to the Security Center-Secret Protection Tool and unbind your secret mobile phone.

I hope I can help you.