Preparation method of lithium iron phosphate positive pole material

The invention discloses a preparation method of a lithium iron phosphate positive pole material. The preparation method comprises the following steps: firstly mixing a lithium compound, a ferric iron compound, a phosphorous compound and a metal element-doped compound, and pouring the mixed raw materials into a reaction kettle, adding deionized water and closing the reaction kettle; opening a stirring and heating device of the reaction kettle, heating until the temperature in the kettle rises to 150-300 DEG C, carrying out hydrothermal synthesis reaction while keeping the temperature, then cooling and relieving the pressure to normal pressure; filtering the product, adding an organic carbon source into the obtained solid precursor, and mixing uniformly; and placing the obtained mixture to inert or weak reducing atmosphere for protection, then roasting at raised temperature, cooling to room temperature, and crushing and sieving the roasted product, thus obtaining the lithium iron phosphate positive pole material. According to the preparation method, the simplicity is realized, the implementation and the industrialization are easy, energy consumption and cost are low, and environmental protection is realized, and the product performance is excellent.