Abstract: In recent years, the rapid development of agricultural water-saving irrigation in China has effectively saved water resources and increased the comprehensive production capacity of land, thereby providing a strong guarantee for the country’s food security. However, relevant research has not yet reached a consensus on the impact of water-saving irrigation measures on the sown area of grain crops. Therefore, based on provincial panel data from 2006 to 2019, this study used the two-way fixed effect model and the moderating effect model to empirically analyze the impact and mechanism of water-saving irrigation measures on the sown area of grain crops with agricultural labor resources as the moderating variable. The study found that 1) in the study year, water-saving irrigation measures could significantly promote the increase in the sown area of grain crops. The promoting effect was more significant effect under less agricultural labor resources, indicating a negative regulatory role of agricultural labor resources. 2) The promoting effect of water-saving irrigation measures on the sown area of grain crops and the negative regulatory effect of agricultural labor resources were found to be mainly reflected in wheat and corn, and their effects on rice were not significant. 3) By re-differentiating the water-saving irrigation measures into modern (spray irrigation, micro-irrigation, low-pressure pipe irrigation) and traditional (canal seepage control) types, it was found that modern water-saving irrigation measures with labor-saving effects could increase the sown area of wheat and corn, and agricultural labor resources still had a negative regulatory effect; traditional water-saving irrigation measures did not have clear labor-saving effects and could only promote an increase in the wheat planting area. Based on the above conclusions, we believed that in the context of the large non-agricultural transfer of agricultural labor resources at this stage, different types of water-saving irrigation measures could be built according to local conditions to promote the sown area of grain crops, thereby ensuring national food security for the realization of rural revitalization and socialist modernization.