Abstract: Global warming has led to frequent extreme events in China, including high temperatures, droughts, and heavy rainfall, severely affecting sustainable socioeconomic development. Agriculture, as a highly climate sensitive sector, is particularly affected. Henan Province, a major grain-producing region in China, has been significantly affected by climate change in terms of grain production. This study analyzed meteorological data from a 1 km resolution dataset of China (1980–2020) and future precipitation and annual mean temperature projections from three CMIP6 climate models. Using trend, mutation, and sensitivity analyses, this study investigated the characteristics of regional climate change and its impacts on grain yield and climatic potential productivity (CPP). The results showed that 1) from 1980 to 2020, the annual mean temperature in Henan Province increased significantly at a rate of 0.038 ℃·a⁻¹ (P<0.01). Annual precipitation showed a non-significant upward trend of 0.50 mm·a⁻¹, demonstrating a warming and humidifying trend in the climate of Henan Province. Spatially, the annual mean temperature increases were relatively uniform across regions, while southern Henan Province had the highest annual precipitation and central Henan Province experienced the fastest decline in sunshine duration. 2) From 1980 to 2020, the grain yield increased significantly. However, the climatic yield exhibited periodic fluctuations and was strongly influenced by droughts and floods. The continuous progress in technology has offset the negative impacts of climatic factors to a certain extent. The volatility of climatic yield and its correlation with climatic factors showed spatial heterogeneity in different regions, influenced by topographical and irrigation conditions. 3) CPP, estimated using the Thornthwaite Memorial model, was found to fluctuate between 10462 and 13921 kg·hm⁻², with an average value of 12368 kg·hm⁻². Its annual increasing trend of 18.99 kg·hm⁻²·a⁻¹ was not significant. Precipitation was identified as the dominant climatic factor influencing CPP. 4) Future projections under all Shared Socioeconomic Pathways (SSP) scenarios (SSP1-1.9, SSP2-4.5, and SSP5-8.5) indicated non-significant increases in CPP from 2030 to 2060 in Henan Province. A low radiative forcing scenario (SSP1-1.9) was found to present more favorable climatic conditions for crop growth. 5) The climatic resource use efficiency in Henan Province was steadily increasing but remained at less than 40%, suggesting that current grain yield has not yet reached the ceiling of climatic potential. To enhance resilience against drought and flood disasters, we recommend maintaining the current land use pattern, optimizing farming practices based on crop characteristics, systematically regulating farmland irrigation, and improving disaster prevention and control capacities.