I have a Gionee mobile phone, but the sim card is made of my mother's name, but my name appears on the phone number. Why?

There is only one possibility in this situation. I used to use my ID card, so your name is always in the card information. Later, because of the transfer, the information was obtained by your mother, but after the transfer, you didn't reissue the card, and the card was still your information. If you ask your mother to fill in the information in the card, it will become your mother's.