According to similarity theory, the paper simulated natural fracture rock through prefabricating crack in simulation material,and analyzed the influence of high temperature and fissure angle on mechanical properties of rock mass under temperature of 20-800 ℃ , and compared the experimental results of white sandstone;based on the Lemaitre strain equivalence principle and macroscopic statistical distribution theory, it established the damage equation of high temperature and loading rock mass.The research results show that before 400 ℃, the mechanical properties of simulation materials and white sandstone are improved with the increase of temperature,after 400 ℃,the mechanical performance begin to degradate,400 ℃ is presumed as the stress-strain curve threshold of white sandstone;the uniaxial compressive strength and longitudinal wave velocity of blocks decrease as the increase of prefabricated crack angle,when the angle is more than 45°,the trend is contrary.The damage of high temperature and loading rock mass is a coupled process of high temperature and stress.The total damages are smaller than the sum of high temperature and load damage.The trend of fracture inclination angle and high temperature effect on rock damage is consistent with the trend of the strength.