I have made a considerable amount of money in the cryptocurrency space. If I withdraw, will the bank question the source of the money?
A bunch of U traders are trying to scare you, making you panic; selling anxiety is really laughable... If it's just a few hundred thousand or a few million RMB, then just find a diamond dealer for bulk trading.
If you really made tens of millions to over a hundred million, get a DBS Bank account in Singapore, prove that your assets are over 5 million Singapore dollars, open a private bank account, which directly supports digital currency conversion to any fiat currency. DBS Bank in Singapore has its own digital currency trading platform, but you need to be a member of the private bank to trade.
Alternatively, you can apply for an elite visa or student visa in Thailand, or a work visa or student visa in Hong Kong; any long-term overseas visa will do. You can open an account legally with the Hong Kong exchange Hashkey using the visa, allowing for legitimate withdrawals.
Those U traders who want to make money off you will really scare you with various cases.