Abstract: "Storing grain in technology" is an important guarantee of stable and high grain production. Based on a panel data of 26 major grain-producing provinces from 2002 to 2020, this research seeks to measure the bias of agricultural technological progress and grain total factor productivity by the three-factor nested CES production function and the DEA-Malmquist model and to analyze the influence of agricultural technological progress bias on grain total factor productivity by the spatial lag model. Results show that, China's agricultural technological progress was non-neutral, and there were differences in the bias of agricultural technological progress at different times, regions, and different food crops. During the research period, China's overall technological progress was biased towards agricultural machinery elements. Different from the agricultural machinery-biased model of wheat, the characteristics of rice and maize had obvious biochemical bias. From 2002 to 2020, the total factor productivity of grain fluctuated significantly, and the comprehensive production efficiency of the main grain producing areas was significantly better than that of the non-main producing areas. Currently, China's agricultural machinery-biased model of technological progress is not conducive to the promotion of the total factor productivity of grain and has obvious negative spillover effects. In addition, biochemical-biased technological progress in non-major production areas has a more significant effect on the total factor productivity of grain. Technological innovation that conforms to the biased characteristics of grain technological progress can better promote grain production and income. Therefore, to promote a virtuous cycle of technological progress and food efficiency, this paper suggests to replace scarce resources with technological innovation, to give a full play to the advantages of agricultural mechanization, and to develop and apply new biochemical technologies according to the endowments of grain production.