Abstract: The auxiliary system of natural gas compressor station is critical to the compressor's stable operation. Once the loss of power happens, the stable operation of auxiliary system will be inevitably interrupted, and even serious accidents may be caused. Therefore, it is quite important to equip a high-performance emergency power supply(EPS). In this paper, EPS energy storage modules were analyzed and compared from the aspect of type and mode, and the hybrid energy storage EPS of supercapacitor and lithium titanate battery suitable for the auxiliary system of compressor station was designed. Circuit design and DC charge/discharge control strategy of EPS system were mainly discussed. Finally, the designed circuit was simulated by Matlab software, based on the parameters acquired in the auxiliary system of Yulin compressor station. And accordingly, the matching capacities of supercapacitor and lithium titanate battery were determined. The simulation results show that this kind of EPS can ensure the normal operation of auxiliary system of compressor station within the stipulated time once the loss of power happens.