If you insist on signing for three years. Then you go to the local international travel health center for a physical examination (you tell them that they need a visa, and the cost is about 300 to 400 RMB), and you can get a health certificate the next day.
Then go to your local police station to apply for a residence permit. If the house is rented, please ask the landlord to write a certificate stating where you live. If you live in a company, ask the company to give you one.
If you have a house on the mainland and live in it, just take the real estate license and the Taiwanese certificate to the police station.
If you need to stay in the mainland for a long time due to work, you must issue a certificate of appointment or a certificate of legal representative (business license). If local people get married, they need a marriage certificate.
Get the above two certificates, the company's employment certificate (or marriage certificate/business license) and some 2-inch photos (I forget how many, please bring more. Some places will ask to take photos at designated places and have contact with the Public Security Bureau. You have to ask clearly so as not to waste your expression and take a picture for nothing. ) Go to the local exit-entry administration to apply for a visa, write the materials and pay the production fee (I sign for one year 100 RMB), and you can get it within 7 working days.