Agriculture is directly related to human survival. The stability and sustainability of agricultural yields is the key to agricultural development. Climate factors not only provide material and energy basis for crops, but also restrict the effective implementation of agricultural technology. Taking maize as the main research object, based on the longterm meteorological observation data in Heilongjiang Province, the MannKendall analysis method was used to calculate the variation trend of precipitation and temperature in maize growth stage. The variation characteristics of precipitation and temperature (maximum, average and minimum temperatures) in maize growing season were revealed. And the principal component analysis (PCA) was combined with the standardized precipitation evaporation index (SPEI), the characteristics of regional drywet changes in the corn growing season of Heilongjiang Province were revealed. The results indicated that the changing trend of precipitation in Heilongjiang Province was not significant, but the changing trend of maximum temperature, average temperature and minimum temperature was significant. The changing trend of wetting was mainly concentrated in the northwest and southeast of Heilongjiang Province. The changing trend of drought was mainly concentrated in most areas of Heilongjiang Province from east to west. The meteorological production of maize was mainly affected by SPEI3-8. Dry and wet conditions SPEI3-8 in June-August were the main factors affecting maize yield. Compared with precipitation, temperature was the main factor affecting the yield of maize in the growth period of Heilongjiang Province. It provided reference for rational planning of regional water resources and optimizing agricultural planting structure.