Abstract: In order to reveal the influence of complementary balance project on grain productivity in tableland area. Taking spring corn and winter wheat as quantitative standards, this paper analyzes the change of grain production capacity and spatial pattern of grain production capacity in Qianyang county, a typical Weibei tableland, from 2016 to 2018 in terms of the proportion and compensation of newly added farmland for three consecutive years. The results showed that the average new farmland in the 2016—2018 complementary balance project ranged from 10 to 12, the implementation of the project raised the average level of new farmland by 1 to 3, which could significantly increase the new farmland, and the proportion of irrigated land area showed a significant positive correlation with the new farmland. There was a significant positive correlation between grain production capacity and new cultivated land area and the average of new cultivated land. Irrigated land accounted for 80.29% of the total new cultivated land area, creating a total grain production capacity of 86.44%.Grain production capacity by arable land, the location, natural conditions, such as water conservancy facilities and road conditions, from 2016 to 2018, relatively flat terrain, climate condition is good, and water conservancy facilities and road condition is relatively perfect Caobi town, the Zhangjiayuan town and the Chengguan town to implement new cultivated land and grain production capacity respectively accounts for 90.16% and 90.49% of the county, and the relative position, the more remote, terrain conditions of poor Nanzhai town, Shuigou town and Cuijiatou Town increased amount of cultivated land accounts for only 10.17% of the total scale, food production accounts for only 9.50% of capacity. During the three years from 2016 to 2018, the implementation of the cultivated land complementary balance project has created 30.82% of the new grain production capacity with 24.89% of the new cultivated land, indicating that the implementation of the cultivated land supplement balance project can significantly improve the grain production capacity of cultivated land.