To solve the reliability problem of automatic three-dimensional material warehouse in sheet metal automatic production line, failure modes and effects analysis(FMEA)of mechanical drive system of material warehouse was carried out using maintenance aware design environment(MADe). The functions and failures of mechanical drive system were defined through standardized classification, and the model of mechanical drive system was established. The propagation path and influence of each failure were analyzed using fuzzy cognitive map (FCM) to generate the FMEA result of mechanical drive system. The results show that the main failure mechanisms are wear, corrosion and deformation, and the main failure causes are insufficient lubrication, pollutant entry and load problems. Thus, a series of targeted improvement measures are put forward to improve the reliability of the automatic three-dimensional material warehouse.