Abstract: The present disclosure belongs to the technical field of lithium battery cathode materials, and discloses a preparation method of multiple carbon-coated high-compaction lithium iron manganese phosphate, comprising the following steps: (1) synthesizing a carbon and vanadium co-doped ferromanganese phosphate precursor through a co-precipitation method, sintering, and removing crystal water to obtain an anhydrous ferromanganese phosphate precursor; (2) adding lithium phosphate, a supplemental phosphorus source, an organic carbon source, a dopant and deionized water, and performing ball milling, wet sanding, spray drying and sintering to obtain an intermediate material; and (3) adding deionized water and the organic carbon source, then performing ball milling, sanding, spray drying, sintering and air jet pulverization to obtain multiple carbon-coated high-compaction lithium iron manganese phosphate.