Laser ultrasonic detection technology possesses unique advantages combining ultrasonic and optical methods, enabling non-contact detection while enhancing temporal and spatial resolution. To enhance the excitation efficiency and defect detection accuracy of laser ultrasound, optimization of laser source parameters is necessary to improve energy exchange efficiency and reduce costs. Research has been conducted on the propagation characteristics of laser ultrasonic sound fields under various conditions. Numerical simulations of the process of laser ultrasonic action on X80 pipelines were performed using COMSOL Multiphysics finite element software, and the accuracy of the model was verified. The relationship between laser source parameters and ultrasonic field was studied by combining the set laser pulse width and laser spot radius, and further analysis of the relevant data was carried out using MATLAB. The analysis results indicate that when the pulse width is set to 20 ns and the spot radius is set to 300 μm, laser ultrasonics exhibit relatively optimal excitation efficiency in X80 pipelines. This provides important reference for improving the excitation efficiency of laser sources.