A simulation system is an efficient tool in laser remote sensing research, effectively advancing system construction and algorithm validation, thereby enhancing research efficiency. To meet the demands of direct scattering spectrum LiDAR for marine remote sensing applications, a comprehensive marine multi-environmental element measurement simulation system was established based on Qt. This system encompasses the laser emission system, seawater channel system, optical reception and spectral measurement system, and signal processing system, achieving full-process simulation. Several simulations were conducted using this system, including system integrity verification and reliability analysis experiments. The simulation results were compared with actual measurement data, showing high consistency and verifying the reliability of the simulation system. The system provides valuable guidance for LiDAR marine remote sensing experiments.