The invention discloses a manganese-iron-lithium phosphate material and a preparation method thereof, a cathode and a lithium battery. The manganese-iron-lithium phosphate material is of a LiMnxFe(l-x-y)MyPO4/C structure, wherein x is greater than or equal to 0 and is smaller than or equal to 1, and y is greater than or equal to 0 and is smaller than or equal to 1; M is a transition metal element, except Mn (manganese) and Fe (iron); the particle size D50 of the manganese-iron-lithium phosphate material is 0.5 to 1.0 mu m, and the particle size D90 is 1.0 to 1.5 mu m; the cohesive force of the manganese-iron-lithium phosphate material is smaller than or equal to 1.5kPa. The particle size of the manganese-iron-lithium phosphate material is smaller particle size, and is 0.5 to 1.5 mu m for particle size D50, and 1.0 to 5.0 mu m for particle size D90; the cohesive force is also smaller and is smaller than or equal to 1.5kPa. The cathode material prepared by the manganese-iron-lithium phosphate material is favorably improving the volume specific capacity of the lithium battery, so as to further prolong the endurance time of the battery.