In order to reveal the variation of microstructure,mechanical properties and phase constitution of Ti-6Al-7Nb alloy with different heat treatment temperatures,the microstructure evolution of Ti-6Al-7Nb alloy was studied at 650 ～ 1 030 ℃ under air-cooled conditions,and the room temperature mechanical properties and XRD of the samples were tested. The results show that tiny alpha phases are precipitated in the original beta transformation structure of Ti-6Al-7Nb alloy after 650 ℃ heat treatment,and the strength and elastic modulus of the alloy are improved. In the range of 700 ～ 850 ℃,the alloy can obtain the good comprehensive performance,and meet the requirement of medical standards. With the increase of temperature in 950 ～ 1 030 ℃,due to the precipitation of secondary acicular alpha phase or the generation of the cubic martensite phase,the strength is increased,along with the plastic declined. At the two temperature points of 650 ℃ and 850 ℃,the XRD spectra of Ti-6Al-7Nb alloy are diffraction peaks of alpha phase without that of beta phase. After heat treatment at 1 030 ℃,the cubic martensite phase has strong( 002) and( 101)diffraction peaks,and the intensity of other lattice orientations is very weak. The elastic modulus of the alloy can reach108 GPa.