In this paper, different indexes which can reflect the running state of all kinds of electric energy metering device equipment are selected to establish the comprehensive evaluation index system. The multi-level fuzzy comprehensive evaluation method is adopted to evaluate the running state. On the basis of state evaluation score, the CAPSO-BPNN forewarning model is built to forecast its future running state evaluation score. Afterwards, the state alarm is raised with reference to evaluation standard. The proposed forewarning method is detailed in combination with concrete numerical examples. The results verified that the method has certain feasibility and can provide theoretical reference basis for the forewarning technology for running state of electric energy metering device.