Due to the uncertainty and anti-peaking naturelarge scale integration of renewable energy imposes greatchallenges to the operation and dispatch of power systems Compressed air energy storage (CAES) system provides new ideas to solve this problem as its characteristics of fastregulating, flexible location and long-service life. Espe-cially, regenerative compressed air energy storage(RCAES) system is widely concerned as its capability ofheat recovery in the compression process. The cycle efficiency is a key indicator of RCAES system which can besignificantly impacted by the key parameters of the systemsincluding compression ratio, exhaust air pressure of throttle(EAPT) and the maximum working pressure (MWP) ofcompressed air storage vessel (CASV). However, currentresearch mostly focuses on the thermodynamic process andfew studies have focused on the impact of key parameters on RCAES system. Based on the efficiency evaluation method which was formulated through the electrical-mechanical-thermal dynamic process and measurable parameters, the impact of key parameters on the cycleefficiency of RCAES system is analyzed in this paper and apractical RCAES design scheme is adopted for case study