Abstract: Through precise simulation of the complete signal process of the Global Navigation Satellite System (GNSS), a reasonable mathematical model of satellite signals is established to generate intermediate frequency signals in various environments, which can provide a good simulation and test platform for the evaluation of the service performance of the GNSS. Modularize and optimize the algorithm for each layer structure of the navigation signal. The navigation message module combined with track simulation software extrapolates the orbital parameters to ensure the authenticity of the message parameters. The data adopts the method of generating the signal in sections and then checking and superimposing. It ensures the alignment and superposition of the multi-layer structure of the signal, ensures the continuity of the signal code and the phase of the carrier, and ensures the stability of the analog source when generating a high sampling rate and long duration signal. The software receiver is used to analyze the signal to verify the effectiveness of the signal analog source.