Why is this personal loan sent to my mobile phone? Did he reserve my mobile phone number?

No, generally, this kind of online loan requires the lender to upload screenshots of his recent calls before lending. If the lender does not repay the loan, he will call the person on the screenshot uploaded by himself and ask him to inform the lender to repay the loan. Then if you know the borrower, the loan company can also find the phone records of you and the borrower in Unicom or Mobile, and then contact you. Texting is only preliminary. I may call you back later.