Abstract: With the rapid development of mobile communication, intelligent manufacturing, automotive electronics, electronic new energy and other emerging fields, reducing the magnetic loss and improving other properties of SMCs are required. The silicone resin mixed with epoxy resin was used to coat the phosphatized carbonyl iron powder (CIP). And the coated powders were fabricated into iron based soft magnetic composites (SMCs) through compression and curing. The effects of different mixed resins on the microstructure and electromagnetic properties of iron-based SMCs were studied. The results show that the mixed resin has been formed a reasonable coating layer on the surface of powders, which leads to reduce the strain of the powders introduced during compression and isolate the powders to cut off the eddy current. As a result, the density of SMCs can reach 6.82 g/cm³, the resistivity is as high as 1.1×10⁶ Ω·cm. Meanwhile, its quality factor is improved and the magnetic loss at high frequency is reduced. When the mixed resin is composed of 33.3wt% epoxy resin and 66.7wt% silicone resin, the SMCs are provided with optimal comprehensive performance with 1182.7 kW/m³ loss only at 200 kHz. The magnetic properties of iron-based SMCs are further optimized through selecting the blending resin coating agent with suitable composition, which has a broad application prospect in the field of medium and high frequency.