How do mainland graduate students immigrate to Hong Kong?

You can consider going to Hong Kong through the Hong Kong Quality Immigration Entry Scheme. You can find the introduction of this scheme, as well as the application qualification and scoring method on the website of the Hong Kong Immigration Department, and calculate whether you can exceed the minimum score limit (now 80 points).

If you have a master's degree and work experience, you can get extra points. If approved, you can get a residence card in Hong Kong and work in Hong Kong. After living in Hong Kong for seven years, you can obtain permanent resident status in Hong Kong.

Otherwise, you can choose to invest in immigration or go to Hong Kong to be a family member through marriage application.