The identification of key elements of smart meters is an important way and means to improve the reliability of smart meters. This article defines the severity of smart meters based on the reliability requirements of smart meters and the actual conditions of smart meters.The FMEA analysis method combined with the actual fault survey data of smart meters is used to evaluate the severity and fault probability level of smart meters, on the basis of which the hazard matrix is drawn to get the identification of the key components of smart meters, and then the key components of smart meters are identified, and the results are in line with the actual situation.