The Mars radiation environment, both in past and at present, plays a vital role in the evolution of Martian atmosphere, so it is necessary to detect the background radiation environment both in the Martian atmosphere and the transfer orbit from Earth to Mars. The Tianwen-1 Energetic Particle Analyzer (EPA) is designed to measure and analyze the energetic charged particles emitted to the Martian atmosphere. Mars-EPA consists of two parts: one is the Mars-EPA sensor head and the other is the Mars-EPA electronics system. This paper begins with an introduction of Mars-EPA structure and function of each part, followed by a simulation of how sensor head structure is designed. It then evaluates the performance of detection system using Geant4 software, to whether this sensor is capable of identifying the target particle and proposes a reasonable ground calibration procedure, which allows on overall detection performance to some degree. This Mars-EPA has demonstrated a potentially high capability and configurability which hopefully will shed light on future development of compact energetic detectors in deep space exploration.