Abstract: Testing studies is made on the mechanical properties of rock salt after undergoing different high temperatures, The mechanical properties include stress–strain curve, peak stress, peak strain, modulus of elasticity. the results indicate that the temperatures is obviously affect the mechanical properties of rock salt, the mechanical properties deteriorate rapidly along with the increase of temperatures, the peak stress and modulus of elasticity decrease rapidly, the peak strain increase rapidly. The peak stress is a power function of confining pressures and temperatures. Based on the relation of elastic modulus and temperatures for rock salt, the thermal damage evolution and one dimensional TM coupled damage constitutive equation are established

Key words: rock salt, high temperature, thermal damage, damage constitutive equation