This paper propose a power supply modeling method to solve the long-distance power supply of marine seismic towed streamer acquisition equipment. Based on the characteristics of power supply structure, the paper establishes circuit model and recursive equation system, and constructs numerical model and forms analysis method combining with the actual parameters such as equipment power consumption, streamer length and power line resistance. Based on this method, a power supply system for marine seismic streamer acquisition equipment is successfully completed, which is also applied to the production of marine oil and gas seismic exploration. And through the actual data of streamer power supply unit, such as voltage and current, the results show that the actual data is consistent with the model analysis results, which verifies the effectiveness of this method.