The invention relates to a preparation method of a carbon-coated porous nano lithium iron phosphate material and a lithium ion battery taking the material as an anode material. The problems that the existing lithium iron phosphate material is poor in conductivity and poor in mass production uniformity, and a performance is poor when a lithium ion battery taking the material as an anode material conducts high multiplying power charging and discharging are solved. The method comprises the steps of 1, weighing; 2, dispersing; 3, preparing a precursor; 4, preparing an intermediate product; 5, preparing a secondary intermediate product; 6, calcining the products; and 7, obtaining the carbon-coated porous nano lithium iron phosphate material. The lithium ion battery taking the material as the anode material consists of an anode plate, a cathode plate, a separation film and an aluminum plastic composite film. The conductivity of the lithium iron phosphate material prepared with the method is improved; the product uniformity is good; and the lithium ion battery taking the material as the anode material is good in performance.