The invention provides a method for preparing micro-sized spherical LiFePo4, belonging to the lithium cell battery material science technical field and the electrochemistry technical field. In the method of the invention, a ferrous sulphate solution and the mixed liquid of diammonium phosphate and ammonium citrate are prepared respectively, while stirring, the ferrous sulphate solution is added in the mixed liquid of diammonium phosphate and ammonium citrate, when the reaction liquids is milk-white, the addition stops, after the reaction is kept for a certain time, reaction liquids are subjected to centrifugation and washing to obtain (NH4)FePO4 with thin grain size; (NH4)FePO4 and LiOH which are the same in mol number are added in a water solution of methyl cellulose and subjected to ultra sonic dispersion to obtain dispersions; the liquid paraffin and Span-80 are uniformly mixed according to a certain ratio, dispersions are added in the oil phase while stirring, after the high-speed uniform stirring, reactants are put in the aqueous thermostat and have water in the sphere slowly evaporated for 3 to 5h and subjected to suction filtering, washing and drying to obtain spherical particles; the spherical particles are subjected to high temperature roast to obtain spherical LiFePO4 materials with the diameter between 5 and 10mu m. For the micro-sized spherical LiFePo4 prepared bythe method of the invention, the tap density is 1.55g/cm<3>, and the stable discharge specific capacity reaches 163mAh/g.