In order to promote the development of agricultural large-scale operation in China, this paper constructs a calculation model for agricultural moderate large-scale operation to estimate moderate operation scale of China’s major crops and different agricultural varieties in different regions based on the analysis of present situation of agricultural moderate large-scale operation. The results show that the national average moderate operation area of grain is 7.3 ha; the average moderate operation area of vegetable, cotton and apple is 0.61, 21.42 and 0.37 ha, respectively; the average moderate scale of hog and sheep is 388 and 234.8, respectively. In addition, for different varieties of agricultural products, we estimate their moderate scale in different provinces. The study provides a scientific basis for speeding up agricultural land transfer and realizing moderate large-scale operation, and sets forth corresponding recommendations on this basis.