Does Sanya require a passport and visa?

No need.

For residents of mainland China, you only need to bring valid identity documents, such as ID cards, household registration books, etc., to travel smoothly to Sanya. Of course, if you are going to Sanya after traveling abroad, you need to hold a valid passport and visa (for countries that require a visa) when entering China. But this process has nothing to do with traveling directly to Sanya, but involves immigration procedures.

In addition, for compatriots from Hong Kong, Macao and Taiwan or foreigners, the specific regulations for traveling to Sanya may be different. Compatriots from Hong Kong, Macao and Taiwan may need to carry corresponding travel documents, such as Hong Kong and Macao Permit, Mainland Travel Permit for Taiwan Residents, etc. Foreigners need to hold a valid passport and visa according to China's entry policy to enter China and travel to Sanya.

In summary:

Mainland Chinese residents do not need a passport or visa to travel or work in Sanya, they only need to bring a valid identity document. Compatriots from Hong Kong, Macao and Taiwan and foreigners need to carry corresponding travel documents or passports and visas in accordance with relevant regulations.

Legal basis:

"Exit and Entry Administration Law of the People's Republic of China"

Article 9:

China When citizens leave or enter the country, they must apply for a passport or other travel documents in accordance with the law.

Chinese citizens traveling to other countries or regions also need to obtain a visa or other entry permit for the country of destination. However, this does not apply unless the Chinese government has signed a mutual visa exemption agreement with the governments of other countries or if the Ministry of Public Security or the Ministry of Foreign Affairs provides otherwise.

Chinese citizens who enter or exit the country as seafarers or work on foreign ships must apply for a seafarer's certificate in accordance with the law.

"Passport Law of the People's Republic of China"

Article 2 stipulates:

The passport of the People's Republic of China is the passport of the People's Republic of China. *Documents issued by the People’s Republic of China to Chinese citizens for international travel purposes. A passport is a form of identification that allows citizens to travel through international ports in various countries. Therefore, you need to apply for a passport when traveling abroad.