Abstract: Based on the middle and late stage soybeans planted in Datong Agricultural Test Station in three sowing dates every year in 1981—2010, 2020 and 2021, the effects of temperature, precipitation and light on the development period of middle and late stage soybeans in the 30 years from 1981 to 2010, 2020 and 2021 are analyzed. It can be concluded that the suitable sowing time of middle and late stage soybeans is May 5 to 12. It is planted too early, there is frost risk, and it is too late to mature, various irrigation methods can be used to alleviate the drought, and the light is sufficient during the growth period of soybean without adverse effects.