In this paper, the laser ultrasonic detection technology in pipeline crack detection is applied to the test of X80 pipeline. The finite element method based on thermal-solid coupling is used to simulate the process of ultrasonic generation by laser irradiation on the pipeline. And from the distribution map of the surface temperature field of the pipeline, the simulation results are analyzed and relevant conclusions are drawn. By studying the propagation characteristics of ultrasonic waves excited by pulsed laser in the pipeline, the vibration curves of ultrasonic waves with and without cracks on the surface of the pipeline are obtained, and the effect of crack depth on ultrasonic surface waves is described. A non-contact experimental platform was established to verify the simulation method. Experiments show that the method can effectively simulate the process of laser ultrasonic detection of pipelines.