Abstract: In a hydrogen leakage scenario, personnel may be exposed to great dangers such as fire, explosion and asphyxiation. In order to effectively reduce the risk of personnel exposure during detection and to monitor hydrogen concentrations in real time. Built upon an open optical path, the system leverages MATLAB's Simulink for visual modeling simulations. The objective is to enhance detection accuracy and signal-to-noise ratio. In pursuit of these goals, a comprehensive comparative analysis of laser scanning parameters is conducted. The study delves into the impact of these parameters on the second harmonic signal waveform and evaluates the influence of different Fresnel lens F-numbers on the light intensity received by the detector. The optimization process involves a meticulous examination of key factors such as peak waveform values, peak width, signal-to-noise ratio, and signal integrity. The findings highlight that the most favorable waveform is achieved with a scanning amplitude of 1 V and a scanning frequency of 10 Hz. Following parameter optimization, the detection range for non-cooperative targets—Wooden boards, lime, plastic, and aluminium sheets—increases significantly. Specifically, the one-way distances for these materials improve from 1.8 m, 2.4 m, 4 m, and 6 m to 2 m, 2.8 m, 5.1 m, and 10 m, respectively. Moreover, the incident power of the laser echo from the system also sees a notable increase. The hydrogen detection system developed exhibits notable features, including a broader range of application environments, a safer detection environment, and heightened detection accuracy. This research serves as a theoretical foundation for selecting relevant parameters in practical measurements and offers guidance for enhancing the system's measurement accuracy in real-world applications.