Abstract: The main parameters of the low floor LRV system powered by lithium titanate batteries and the composition of lithium battery power supply system were introduced. The calculation of the main parameters of the battery pack according to the needs of the completed vehicles was completed. The simulation model of on-board energy storage system was established, and double closed-loop control method was used to carry out simulation verification on the energy storage power supply system. The working mode of the traction system under two typical working conditions, that is, the contact lines and energy storage power supply, is analyzed. The actual measurement of the line was carried out on Changchun Light Rail Line 4, and the rationality and stability of the vehicle's traction system design was verified by the actual measurement results.