A person without domicile in China is generally considered a Chinese tax resident if they spend 183 days or more in China during a calendar tax year (January 1–December 31). China applies a special day-counting rule for non-domiciled individuals: a day is counted only when the stay in China lasts 24 hours or more on that day, so arrival and departure days may not count. People domiciled in China may be tax residents regardless of the number of days spent in China. This tracker therefore represents the 183-day physical-presence test only.
https://www.chinatax.gov.cn/eng/c102962/c102967/c102997/c103004/c5245849/content.html