The invention discloses a CAN communication message analysis method for a vehicle-mounted controller, including analyzing a DBC file to generate a configuration code; judging whether the CAN message contains the Can message Id in the configuration code, and if the Can message Id is included Then search for the signal list according to the Can message Id, and if the Can message Id is not included, the parsing ends; judge the signal arrangement format of the CAN message, and intercept the original data in the CAN message according to the signal configuration information, and calculate the physical value Information; assign the physical value to the global variable in the configuration code; judge whether the last signal of the CAN message is reached, if it is the last signal of the CAN message, then end the parsing, if it is not the last signal, repeat this method until the CAN The last signal parsing of the message is complete. The invention also discloses a CAN communication message construction method of the vehicle controller. The CAN communication message analysis and construction method of the vehicle-mounted controller of the invention can flexibly deal with various DBC files and improve the development efficiency of the ECU.