All right, with your version of the airfare, you need to make out an individual Chinese visa, since visa-free entry into Sanya provides for arrival and departure by international flights, and you fly through all country with two transfers . Visa-free transit through some cities of China is also applicable only to international flights in the case of an international flight - China - an international flight, there is a controversial issue about the transit to a third country through several Chinese cities, for example: Mos kw - Urumqi - Guangzhou - Melbourne, if the total time of stay in the PRC is less than 24 hours, but this is also not your case, since you follow through 2 Chinese points to the third Chinese city . I have repeatedly explained on this question earlier in the answers: "Do I need a visa when flying to Hainan through Guangzhou", "Do I need to issue a Chinese visa when flying to Australia, if the time in China is less than 24 hours" .

Yes, following the route Heihe - Beijing , Beijing - Sanya you need to issue a Chinese visa.

Transit visa is valid for 72 hours, if you have a visa of the main destination country (for example, Hong Kong). You can also get a visa upon arrival in Sanya. Visa is issued in 5 working days. Pay attention to the most important point: you can get such a visa only at Sanya airport - nowhere else. That is why it is necessary to buy an air ticket for a direct flight to Sanya (for example, Moscow-Sanya, Hong Kong-Sanya, etc.), and not to Shanghai, Guangzhou or any other city in China.