Abstract: The relationship between the particle size and specific surface area of molybdenum powder was studied by measuring the Fei’s particle size, size distribution, particle size, microstructure and specific surface area of molybdenum powder, and combining theoretical calculations. The results show that the specific surface area of molybdenum powder was inversely proportional to the average particle size, and the relationship rule between particle size and measured specific surface area resulted roughly conforms to the trend of theoretical calculations. When the shape of molybdenum powder particles was spherical, the more uniform the particle size and the lower the degree of agglomeration, the closer the measured specific surface area results were to the theoretical calculation results.