Ultrasonic velocity has a direct influence on defect detection and characterization of materials,therefore,it is important to study the variation law of sound speed at different temperatures.In this paper,the propagation velocity of longitudinal wave,transverse wave and surface acoustic wave excited by laser point source at different temperatures are numerically simulated by finite element method,the relation between sound velocity and temperature of longitudinal wave,transverse wave and surface acoustic wave is obtained.According to the expression,Poisson′s ratio and elastic modulus are derived at high temperature.The results show that the sound velocity of longitudinal wave,transverse wave and surface acoustic wave decrease linearly with the increase of the temperature,and the change rate with temperature is 0.8374 m·s-1· ℃-1、1.203 m·s-1· ℃-1、1.096 m·s-1· ℃-1,respectively.According to the expression of the sound velocity and temperature,the elastic modulus and Poisson′s ratio at high temperature are derived,and compared with the theoretical values,the errors are 3.16% and 4%,respectively.