Theoretical analysis of the failure characteristics of measuring boxes is based on the high altitude environmental conditions. This paper uses the component criticality assessment method to evaluate each component of the electric energy metering box, confirm the key components, and then conduct risk assessment on the key components through failure mode and impact analysis to determine the failure mode and phenomenon of the key components. We classify and summarize various faults of key components, form a fault library for on-site operation of electric energy metering boxes, develop a fault library and grade evaluation software for metering boxes, and conduct correlation analysis on factors affecting electric energy metering box faults. Failure mechanism and fault analysis can improve the safety and stability of the operation of electric energy metering equipment, ensuring the safety of electricity consumption and cost control reliability of the power grid.