Abstract: Interfaces play a key role in the load transfer of particle reinforced composites, and the interface properties have an important impact on the overall mechanical behavior of composites. However, due to the complex internal structure of composites, it is difficult to determine the interfacial strength and fracture toughness, especially for the respective prediction of normal and tangential interfacial strength. In this paper, a new method is proposed to predict the interfacial mechanical properties of particle-reinforced composites based on zirconia particle (ZrO) reinforced polydimethylsiloxane (PDMS) composite materials. Firstly, the uniaxial tensile stress-strain curves of pure PDMS matrix material and single particle filled PDMS sample are obtained, and the uniaxial tensile constitutive relationship of the PDMS matrix material is achieved. Secondly, the finite element model (FEM) consistent with single particle filled sample is established, and a specific cohesive zone model is chosen to describe the mechanical behavior of interface. Comparison of the experimental and numerical results of tensile mechanical response of samples at different stages can yield the normal strength, tangential strength and fracture toughness of the interface, respectively. The achieved interfacial mechanical parameters are further adopted in FEM calculations of samples filled with different sizes and numbers of particles. The rationality of the proposed method of predicting interfacial properties is verified by comparing the corresponding experimental and numerical results. Such a method is simple, easy to operate and has high accuracy, which should be helpful to quantitatively predict the mechanical property of particle reinforced composites, and also has certain reference significance to quantitatively predict the interfacial properties of fiber reinforced composites.