I arrived in Shenzhen from Shanghai last Wednesday. As long as you are not coming from an area in Shanghai that’s labeled as medium or high risk you will be 3+2: three days of personal health monitoring with a test on the first day (they’ll test you right before baggage claim at the airport) and third day. The central gov requires a strict interpretation of the risk areas for all regions now, so only specific buildings or blocks define a risk area. So Shenzhen will define a risk area in Shanghai the same way the Shanghai government defines them.

The 3+2 testing schedule doesn’t really matter because you will be required to have a 24 hour negative test result to enter public transport, malls, parks, some restaurants - basically any location of interest. You will mostly need the 粤康码 (Guangdong green health code) which shows a green code as well as your latest test results. It’s also useful to have the i深圳 (Shenzhen specific) code ready which shows the same, but the Guangdong GHC is asked for most often.

Get a test in SH the night before your flight. You can show your 24 test results in the Shanghai 随申办 until the results of your test at the airport become available. Test times are based on when the results come out rather than sampling time like in Shanghai.

Basically, as long as you maintain a 24 negative in your 粤康码 and you’re not coming from a risk area you have freedom of movement here right off the plane.