The factors influence the mechanical properties of the Ta/W composite prepared by CVD was investigated by tensile test, optical microscopy(OM), scanning electron microscope(SEM ). The results show that the volume fraction of W, the time and temperature of heat treatment affect the mechanical properties of Ta/W composite observably. The composite with 13%W could afford perfect Tensile strength and ductility. The appropriate heat treatment is 1600×2h which could more powerful to enhance the mechanical properties of the Ta/W composite, and the essence of heat treatment influence the mechanical properties of the Ta/W composite was changed the size of composite grain and the thickness of diffusion layer.