Abstract: In order to achieve temperature measurement of specimens with surface cracks in hightemperature working environments, a new approach was proposed to use the time-frequency parameters of laser ultrasonic Rayleigh waves to achieve temperature measurement of surface crack specimens. This article used the steady-state solution as the transient initial value of the temperature loading method to establish a surface crack specimen model of structural steel within the temperature range of 293. 15～743. 15 K, and analyzed the interaction between laser ultrasonic Rayleigh waves and surface cracks. In the time domain, the normalized peaks of Rayleigh reflection and transmitted waves were used to define the two time-domain parameters of reflectivity and transmittance, and it was found that both reflectivity and transmittance increase linearly with temperature, and the change rates of reflectivity and transmittance with temperature were 1. 45 × 10^-3 dB · K^-1 and 2. 3 × 10^-3 dB · K^-1, respectively; In the frequency domain, the characteristic extreme point relationship method of ultrasonic energy intensity under the wavelet TFA（time-frequency analysis） distribution of Rayleigh wave was proposed, and the linear growth rate of the characteristic extreme value of energy intensity with temperature was 2. 56 × 10^-4 dB · K^-1 when the characteristic frequency was 2. 4 MHz; experimental analysis proved the feasibility of simulation results.From the research of time and frequency domains combined with experimental analysis, it is shown that the temperature measurement expression of the specimen with surface crack can be realized by using the linear relationship and change rate of time-frequency parameters and temperature.