Ba0.6Sr0.4TiO3 powder was prepared by sol-gel method, and Ba0.6Sr0.4TiO3 was mixed with FeNi alloy powder by ball milling method. FeNi/Ba0.6Sr0.4TiO3 composite with three different Ba0.6Sr0.4TiO3 powders was successfully prepared. The morphology and composition of FeNi alloy micropowder before and after the addition of Ba0.6Sr0.4TiO3 were analyzed by scanning electron microscopy and X-ray diffractometry. The electromagnetic parameters of FeNi and FeNi/Ba0.6Sr0.4TiO3 composites were measured by vector network analyzer.. The results show that the irregular granular Ba0.6Sr0.4TiO3 powder can be successfully prepared. The Ba0.6Sr0.4TiO3 powder is mostly coated on the surface of the flake FeNi alloy powder, and with more Ba0.6Sr0.4TiO3 powder addition, the thickness of the coating gradually increases, and the shape of the FeNi alloy is gradually blurred. The Ba0.6Sr0.4TiO3 powder coating layer effectively reduces the dielectric loss of the FeNi alloy micropowder, improves the impedance matching performance in the low frequency band, and improves the low frequency absorbing performance. The relationship between the peak frequency of reflection loss and electromagnetic parameters was analyzed by 1/4 wavelength interference cancellation theory. The reflection intensity peak intensity was analyzed by interface reflection model and material impedance matching.