It won't.

Not actually a bad thing it makes mining profitable for people in other countries with a lot of "cheap" used ASIC miners going for the taken, if China bans mining. On top of that they won't ban producing the mining equipment (that is just electronics) so prices will drop for equipment as they want to ramp up exporting them from China (China has been guilty of making sure production of ASIC miners stays mostly in China).

It will be into the 22nd century (I know long time) before the last BitCoin is mined so I can think of a few countries, those who have strong renewables, that would jump at this opportunity to have no competition from China in mining.

I don't think China will ban using BitCoin so the Chinese will still demand it and use it via Macau and Hong Kong to get funds out of China. That is inevitable.

Either way BitCoin wins when you think about it. China just can't break BitCoin. It is not that simple. So don't worry about it. I am not.

Caveat is BitCoin cash will be destroyed if it happens as all their operations are in China and need China. I don't think they will find it easy to restart mining in other countries becasue of their fugazi nature (something China embraces but the rest of world finds deplorable).