Can school-age children not write their previous names in the household registration book after changing their names? Will it affect emigration in the future?

No, as long as you register in the household registration book, you will use your name. That's my son. He is very helpless. It will be convenient when China can cancel the household registration policy, so you should pay attention to it. You can only change your name once in your life. Be sure to think about it before you go to the police station to register this time!