Why does Shenzhen cashier need a copy of the property as a guarantee? Will it be bad for the future?

You applied for a cash cashier, right? This guarantee is necessary, and the company is also considering funding arrangements. The copy of the real estate license can indicate that the use is limited to the cashier's work certificate. So it cannot be used for other purposes.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.