The invention relates to a 
coating method for iron-based magnetically soft 
alloy powder and a preparation method of 
soft magnet composite material. The 
coating method for iron-based magnetically soft 
alloy powder comprises the following steps: carrying out accelerated oxidation on iron-based magnetic 
metal powder at high temperature, forming an 
oxide layer on the surface of the powder and then carrying out acid 
pickling, thus obtaining powder with surface coated with SiO2, Al2O3 and Cr2O3 oxides. The preparation method of the 
soft magnet composite material comprises the following steps: adding 
coupling agent, 
silicon resin and lubricating agent to the coated powder, carrying out pressing forming, and then carrying out annealing heat treatment, thus obtaining the 
soft magnet composite material. According to the invention, the 
advantage that an 
oxide produced in reaction of elements including Si, Al and Cr contained in the iron-based magnetically soft 
alloy powder with 
oxygen is high in electrical resistivity, small in 
thermal expansion coefficient and steady in chemical performance and can 
resist high temperature is fully utilized; the adopted 
coating technology is to produce a coating layer in situ on the surface of the alloy 
magnetic powder, and is simple in process, easy to operate and low in cost; the 
metal soft 
magnet composite material prepared by adopting the method disclosed by the invention has good magnetic property and frequency stability.