Based on statistical agricultural data and daily meteorological data for 39 national-level meteorological stations in Henan province and surrounding areas from 1980 to 2015, we analyzed spatio-temporal changes in hydrothermal conditions during the growth stage of main grain crops. The sensitive effect of main crop yield to changes in climate factors was explored using nonlinear regression. We found that the regreening stage minimum temperature and mean temperature in the growth stage of winter wheat increased significantly: the rate of increase decreased from the center to outside Henan. The sunshine duration of the summer maize growth period decreased significantly, furthermore, central Henan was the fastest reduction area in sunshine duration while southwestern Henan had the slowest reduction. The yield of winter wheat and summer maize exhibited the largest sensitive effect to mean temperature and sunshine duration during the growth period, and both exhibited the smallest sensitive effect to precipitation during the growth period. However, the sensitive region of both caused by the precipitation during the growth period was the largest, accounting for 33.3% and 22.2% respectively. After change in climate factors, mean temperature in the growth stage of winter wheat was beneficial to the rise of winter wheat that grew in the area except for northern Henan, accounting for 83.3% of Henan. However, the regreening stage minimum temperature more easily augmented winter wheat growing in northern and eastern Henan, accounting for 44.4% of Henan. Sunshine duration in the growth stage of summer maize was more beneficial to increased summer maize that grew in central and western Henan, accounting for 44.4% of Henan.