The development of smart grid needs to provide a variety of communication protocol mapping methods for substation, and put forward higher requirements for communication performance. At present, most substation communication is based on IEC 61850 standard, so it is difficult to convert substation communication directly to lightweight protocol. In this paper, a multi protocol communication mapping method is proposed, which combines the concise binary object representation (CBOR) format to map IEC 61850 to constrained application protocol (COAP). Compared with the existing mapping schemes such as ws-soap and HTTP, COAP + CBOR only needs 44% and 18% of the information size and 71% and 85% of the communication time, which alleviates the problem of limited equipment and network resources in power grid. In addition, COAP has a REST based architecture, which supports system integration through unified identification and interaction, and has interoperability. This method promotes the communication compatibility and integration of traditional platform with Smart Substation and power grid automation system.