The finite element model, which considered the interfacial reaction layer was developed to evaluate interfacial shear strength of titanium matrix composites (TMCs) and analyze the effect of interface reaction on interfacial mechanical properties. The results show that the interfacial shear strength of SiC/Timetal-834 evaluated is about 500 MPa, and that the interfacial shear strength increases as the interfacial reaction enhances. Moreover, the relationship between the thickness of the interfacial reaction layer and the interfacial shear strength is built.