The invention relates to the technical field of phosphor powder preparation, and particularly relates to a preparation method of molybdate red phosphor powder. The method includes the steps of: firstly preparing a molybdate red phosphor powder semi-finished product; then according to a mass ratio, putting 47-95 parts of Zn(NO3)2.6H2O, 20-40 parts of H2BDC and 3-50 parts of the molybdate red phosphor powder semi-finished product into N-methyl pyrrolidone in order, and conducting ultrasonic oscillation dissolving to obtain a mixed solution; then placing the mixed solution in a constant temperature environment for reaction to obtain a molybdate red phosphor powder initial product containing MOF; and finally, cleaning and drying the molybdate red phosphor powder initial product containing MOFto obtain molybdate red phosphor powder containing MOF. The method provided by the invention combines a metal organic framework MOF material with nano phosphor particles, utilizes the high specific surface area and high porosity characteristics of the MOF material to realize dispersion of nano phosphor particles in the MOF material, and overcomes the defect of low luminous efficiency of nano phosphor particles in the prior art, thus achieving the purpose of improving the luminous efficiency of phosphor powder.