Ternary layered Ti3SiC2 ceramic is a new kind of ceramic material, which has the characteristics of low density and high melting point. As reinforcement phase, it can obviously improve the mechanical properties and friction and wear properties of Ti3SiC2/Cu composites. However, the decomposition of Ti3SiC2 in the sintering process results in the change of microstructure and properties of the composites. In order to suppress the decomposition of Ti3SiC2 and improve the properties of composite materials, the surface of Ti3SiC2 particles was modified by multi-arc ion plating Ti, and the composite materials with excellent interface properties and undecomposed Ti3SiC2 particles were prepared. The decomposition of Ti3SiC2 in composites and the inhibition mechanism of Ti element on its decomposition were studied, and the microstructure evolution of composites with different contents of Ti3SiC2 was analyzed. The results show that the deposition of Ti element on the surface of Ti3SiC2 can effectively inhibit the decomposition of Ti3SiC2 particles in the sintering process of copper matrix composites.