The work aims to improve the microwave absorption performance of (SiC)P. The surface of (SiC)P was modified by low-cost and eco-friendly electroless nickel plating method. The oxidized, hydrophilic, sensitized and activated series enhanced pretreatment process was designed to determine the best surface modification flow of (SiC)P. The morphology, composition and phase of (SiC)P before and after plating were characterized by SEM, EDS and XRD. The dielectric properties of the modified (SiC)P powder were measured by waveguide method. On an aluminum substrate, the obtained sample was made into the wave absorbing material. A high-quality modified silicon carbide composite powder with a continuous coating and no smooth (SiC)P bareness was obtained ((Ni/SiC)P). After modification, the morphology, composition and structure of (SiC)P were significantly changed, and the dielectric constant, dielectric loss and absorbing properties had an obvious improvement. Among them, the real permittivity increased by 22% and the imaginary permittivity increased by 20%. When one-layer (Ni/SiC)P was coated on the sample, the reflection loss (RL) reached -15.47 dB at 17.12 GHz, which was more than absorption performance of two-layer (SiC)P coating. After two-layer (Ni/SiC)P was coated, the RL of absorber reached -23.51 dB at 16.11 GHz. High quality modification of (SiC)P surface can be achieved by low cost and environmental protection method. After modification, the dielectric properties and wave absorption performance of (Ni/SiC)P particles are significantly improved.