Abstract: The composition of TA15 titanium alloy was predicted by JMatPro software, and the thermodynamic phase diagram under equilibrium conditions was obtained. Through the analysis of the change of the concentration of the main phase components, it is known that its content is very little affected by neutral elements. The heat treatment properties, martensitic transition process and thermal properties of TA15 titanium alloy were calculated, and the rheological curves, martensitic phase diagrams of different cooling rates, and the variation curves of density, thermal conductivity, resistivity, Young's modulus, specific heat capacity, heat enthalpy, expansion coefficient and other properties were obtained. During the cooling process, the faster the cooling rate, the more martensitic phases are in the product. Fine martensitic can improve the ultimate strength of the material, but it will reduce the body modulus and Young's modulus, and affect the fatigue performance of the material. Therefore, in heat treatment, it is necessary to control the cooling method to change the martensitic content in the tissue to ensure that the parts meet the performance requirements.