A method for preparing rare earth permanent magnet material comprising: step 1, weighing powders of three raw materials, H, M and Q according to the atomic percentage content in a general formula H 100-x-y M x Q y, and performing the mixing treatment and sieving treatment sequentially on the three raw materials in a nitrogen gas or other oxygen-free environments to obtain a composite powder; wherein: in the general formula, H is one or more in fluoride or oxide powders of Dy, Tb, DyTb, Ho and Gd, M is Nd or/and Pr metal powder(s), and Q is one or more in Cu, Al, Zn, Ga and Sn metal powders, x and y are respectively the atomic percentage contents of the raw material M and the raw material Q, x=1-15, y=4-25; step 2, machining a sintered NdFeB magnet into a prescribed shape and size, and then performing the surface cleaning and drying to obtain a NdFeB magnet to be treated; step 3, adhering the composite powder to the surface of the NdFeB magnet to be treated by static electricity in an oxygen-free environment to obtain a NdFeB magnet, the surface of which is adhered with a composite powder film, wherein: the composite powder is sprayed onto the surface of the NdFeB magnet to be treated by an electrostatic spray gun; in which, technological conditions are as follows: the voltage is 30-120 kv; the time is 5-40 s; the movement speed of the spray gun is 5-45 cm/s; the spray distance is 8-35 cm; wherein the thickness of the composite powder film is 10-40 μm; step 4, performing vacuum thermal treatment on the NdFeB magnet, the surface of which is adhered with a composite powder film, and then furnace cooling to obtain a diffused NdFeB magnet; step 5, performing tempering treatment on the diffused NdFeB magnet to obtain the rare earth permanent magnet material. step 1, weighing powders of three raw materials, H, M and Q according to the atomic percentage content in a general formula H 100-x-y M x Q y, and performing the mixing treatment and sieving treatment sequentially on the three raw materials in a nitrogen gas or other oxygen-free environments to obtain a composite powder; wherein: in the general formula, H is one or more in fluoride or oxide powders of Dy, Tb, DyTb, Ho and Gd, M is Nd or/and Pr metal powder(s), and Q is one or more in Cu, Al, Zn, Ga and Sn metal powders, x and y are respectively the atomic percentage contents of the raw material M and the raw material Q, x=1-15, y=4-25; step 2, machining a sintered NdFeB magnet into a prescribed shape and size, and then performing the surface cleaning and drying to obtain a NdFeB magnet to be treated; step 3, adhering the composite powder to the surface of the NdFeB magnet to be treated by static electricity in an oxygen-free environment to obtain a NdFeB magnet, the surface of which is adhered with a composite powder film, wherein: the composite powder is sprayed onto the surface of the NdFeB magnet to be treated by an electrostatic spray gun; in which, technological conditions are as follows: the voltage is 30-120 kv; the time is 5-40 s; the movement speed of the spray gun is 5-45 cm/s; the spray distance is 8-35 cm; wherein the thickness of the composite powder film is 10-40 μm; the voltage is 30-120 kv; the time is 5-40 s; the movement speed of the spray gun is 5-45 cm/s; the spray distance is 8-35 cm; wherein the thickness of the composite powder film is 10-40 μm; step 4, performing vacuum thermal treatment on the NdFeB magnet, the surface of which is adhered with a composite powder film, and then furnace cooling to obtain a diffused NdFeB magnet; step 5, performing tempering treatment on the diffused NdFeB magnet to obtain the rare earth permanent magnet material.