What about the credit card when the mainland ID card cancels immigration?

You can cancel it if you don't use it. If you use it, you can update your information. Basically, this matter has little to do with the credit card after immigration.

/10 2003 On June 27th, 2003, the government of the Hong Kong Special Administrative Region implemented the entry plan for capital investors with a threshold of HK$ 6.5 million. Investors can choose their own investment projects from the types of allowed investment assets, without starting or jointly organizing business. After the investment is completed, it will be issued to temporary id card, and it will enter the country twice a year, once every two years and three times every seven years. After the investment is maintained for seven years, a Hong Kong permanent identity card will be issued. During this period, the applicant shall not mortgage his investment to banks or other institutions in any way, and withdraw funds to leave Hong Kong. If they violate this condition when investing in Hong Kong, their immigration qualification will be terminated.