The existing record units of on-board rail vehicle equipment, due to insufficient protection, might be damaged, which would result in data lost in case of accident. Besides, different recording time and analysis software made it difficult to analyze. To solve these issues, protective recorder was designed in CMD system based on IEC 62625 standard. Through the recorder, data from different onboard equipment was recorded in unified format in a fire-proof, anti-vibration and liquid-proof data storage unit, free from loss or damage. The operating status could also be analyzed in a comprehensive way via unified ground analysis software.