Are the police not allowed to marry foreigners, not allowed to go abroad without permission, and immigrate in the next few years?

Actually, it's a bit troublesome, because the police is a special post. Although your job does not involve national security, you are an ordinary policeman, but the country still lists you as a classified person, but the level of confidentiality is not that high, but there is still a confidentiality period, that is, if you want to go abroad after retirement, you must get approval from a special department before you can leave the country. The Canadian government doesn't care whether you are a policeman or not, but China will restrict you from leaving the country for personal reasons. For example, some people don't approve or even get personal passports.