A method of manufacturing a positive electrode material has the steps of synthesizing an iron metal in a phosphoric acid solution to form an iron phosphate dispersion solution; adding a vanadium pentoxide (V 2 O 5 ), a non-ionic surfactant and a carbon source to the iron phosphate dispersion solution; and adding a lithium salt to the iron phosphate dispersion solution and then grinding and dispersing it to produce a positive electrode material. By regulating the timing of the addition of vanadium pentoxide (V 2 O 5 ), the present invention enables the battery made of the positive electrode material to have the advantage of higher battery performance.