In order to avoid missing key message caused by sending fault of CAN node in mine-used new energy electric locomotive, a sending fault tolerant method of CAN bus based on TTCAN protocol was proposed, that is, message sent unsuccessfully by CAN node will be resent until the message is sent successfully or resending times reach the maximum resending times. At the same time, a high-efficient receiving and processing message method of CAN bus was proposed. Message is cached during interrupt receiving message, meanwhile, amount of received message is modified, and message in cache is processed by main program based on the modified amount, which realizes time-sharing operation between receiving and processing of message. The test results show that the optimization method can improve real-time ability and reliability of CAN bus communication effectively, decrease working time of CPU in each CAN node and improve working efficiency.