At present, the communication of most substations is based on the IEC 61850 standard, but its performance is lagging behind modern communication technology, which hinders the comprehensive transition of the substation to intelligent lightweight communications. To this end, a communication mapping method is proposed, which combines the confident binary object representation (CBOR) format and maps the IEC 61850 standard to the constrained application protocol (CoAP). Firstly, a COAP mapping URI and request method of commonly used IEC 61850 services are given. Secondly, the COAP subscription mode is expanded to resolve the IEC 61850 to COAP mapping requirements. Finally, the communication mapping model is set to verify the effectiveness of the proposed method. Compared to existing WS?SOAP and HTTP mapping schemes, COAP+CBOR requires only 44% and 18% of information size, 71% and 85% communication time, which alleviates the problem of limited equipment and network resources in the power grid.