The problem of domestic patents entering overseas markets

Well, the patent right is regional, and the patent right of a country (region) is only valid locally. So having a patent right in China does not prevent others from obtaining the same patent right as you abroad, unless your patent has been made public when others apply for a patent abroad.

Within 12 months after your application date, if you apply for a patent in Paris Convention or PCT allies or other countries that have signed agreements with China, you can enjoy priority in China.

If you want to apply for a patent abroad, I suggest you file a PCT application with the Chinese Intellectual Property Office, and then enter other PCT allies for substantive examination according to the PCT Treaty, which should save more time, effort and money.