New agricultural business entities， represented by agricultural enterprises， are important drivers of agricultural modernization. However， it remains uncertain whether their production and operational activities are encroaching on food production resources or promoting grain yield improvement. This study utilizes the number of newly established agricultural enterprises at the municipal level from 2010 to 2019 to measure the degree of agricultural enterprise development in different regions. Subsequently， a two-way fixed effects model is constructed to examine their impact on grain yield. The results are as follows： 1） The agricultural enterprises significantly promote grain yield improvement. 2） The mechanism through which agricultural enterprises enhance production involves promoting large-scale cultivation and mechanized production， thereby improving resource utilization and enhancing agricultural productivity. 3） The effectiveness of agricultural enterprises in increasing yield exhibits noticeable heterogeneity with regard to regional resource endowments. Specifically， agricultural enterprises can enhance yields in grain-producing regions with favorable natural resource endowments in the short term. However， the yield-enhancing effects of agricultural enterprises in non-grain-producing regions become apparent after long-term operations. The abundance of human resources is crucial for agricultural enterprises to realize their yield-enhancing potential， with regions having a higher abundance of human resources exhibiting stronger effects from agricultural enterprises. 4） In regions with a more favorable business environment created by the government， characterized by higher levels of fixed asset investment or a larger proportion of public expenditure relative to GDP， the yield-enhancing effects of agricultural enterprises are greater. To effectively maximize the important contribution of agricultural enterprises in promoting food security， it is necessary to create a favorable business environment alongside effective markets and proactive government while ensuring an adequate supply of resources.