In this paper ,the molybdenum powder of spherical, micron size, large specific surface area and good dispersion was prepared by spray drying and microwave calcination, and ammonium paramolybdate (GR pure) as raw material. The effect of spray drying and heating rate of microwave calcination on the surface morphology, particle size and specific surface area of the final Mo powder was studied. Research results show that the Mo precursor powder of spherical, micron size and good dispersion was prepared by controlling parameters. The micro morphology of the final Mo powder is affected by the heating rate. When the heating rate is low, the Mo powder is broken more serious and had a small amount of aggregation . The Mo powder with well spherical and good dispersion was prepared, when the heating rate is becoming higher. The heating rate also directly affects the average particle size and specific surface area. The lower the heating rate, the smaller the average particle size, and the larger the specific surface area. The average particle size is becoming bigger and the specific surface area is becoming smaller when the heating rate is higher.