The microstructure of particle-reinforced metal matrix composites (PMMCs) and its parameters (such as particle size distribution, particle volume fraction, particle shape, etc.) have a great influence on the elastic modulus of PMMC. In this paper, the intermingled fractal units (IFU) model was used to describe the microstructure of PMMCs. Based on the spring series-parallel connection model, an analytical method of predicting the elastic modulus was proposed, and the area fraction, size distribution, and interface of the reinforced particles were taken into consideration. The tensile experiments performed on three groups of the SiC/Al composite specimens with different microstructure (namely, of different particle shape, size, and volume fraction of reinforcing particles) were conducted to evaluate the elastic modulus and strength properties. The comparison between the predicted and experimental results has proved the applicability and effectiveness of the method proposed in this paper.