The present disclosure relates to a cathode material for a lithium ion battery, and a preparation method therefor. The cathode material is a Ti3C2 MXene-coated lithium manganese iron phosphate material, Ti3C2 MXene being uniformly coated on surfaces of lithium manganese iron phosphate nanoparticles and forming an electrically conductive mesh. The preparation method therefor comprises: adding a phosphorus source and a lithium source to a deionized water/PEG solution, to form a suspension A; adding a manganese source, an iron source, an antioxidant, and Ti3C2 MXene to deionized water to form a suspension B; adding the suspension B to the suspension A dropwise under continuous stirring, to form a mixed solution; then transferring the mixed solution to a hydrothermal reactor to maintain temperature; and after reaction is complete, centrifugally separating a product, and then performing washing, drying, and annealing to obtain the material. In the present disclosure, Ti3C2 MXene is used to coat the surface of the lithium manganese iron phosphate material, effectively improving the ion and electron transmission capacity and structural stability of the lithium manganese iron phosphate material; making it quite suitable for use as a high-energy and high-power-density cathode material for a lithium ion battery.