The invention provides a preparation method of spherical lithium iron phosphate, which belongs to the technical field of lithium battery anode materials and solves the problems of low tap density, low conductivity, irregular shape, unstable performance, poor post-processing affinity, and the like of lithium iron phosphate prepared by the preparation method of the prior lithium iron phosphate. Thepreparation method of spherical lithium iron phosphate comprises the following steps: A, preparing lithium iron phosphate powder; and B, preparing the spherical lithium iron phosphate. The preparation method of the spherical lithium iron phosphate has simple technical process and low production cost and is suitable for large-scale production. The prepared spherical lithium iron phosphate has small granularity, large tap density and high first discharging specific capacity at room temperature.