Abstract: The thermo hydrogen treatment was performed on (TiB, TiC)/Ti-6Al-4V composites prepared in situ reaction, and the microstructure and mechanical properties of the composite in different states were studied. The results show that hydrogenation decreased the phase transformation temperature and increased the β phase content. α and β phases were obtained in the composite with 0 and 0.15wt% H after hot-forging, while α′′ martensite and β phase was obtained in the composite with 0.6wt% H. Dehydrogenation treatment increased the yield strength and tensile strength of the composite at room temperature and at 400 ℃。