Electric vehicle charging monitoring method, device and system

The invention provides an electric vehicle charging monitoring method, device and system, wherein, the electric vehicle charging monitoring method applied to a charging pile includes collecting firststate information of the electric vehicle connected with the charging pile and second state information of the charging pile; storing each item of data in the first state information and the second state information in a corresponding OPC data item respectively; adding OPC data items subscribed by the monitoring terminal to the same OPC group; when the data change in the subscribed OPC data item exceeds the first amplitude threshold, the OPC group is updated and the data of the OPC data item in the OPC group is sent to the monitoring terminal. The invention adopts the OPC protocol to standardize the data exchange between the charging pile and the monitoring terminal, and the monitoring terminal can access different charging piles through the standard OPC interface without writing a specialdriving program, so that