In order to realize the calibration for different electronic control unit (ECU) with the same platform, a solution for universal ECU calibration of electroniccontrolled diesel engine based on controller area network (CAN)  and extended CAN calibration protocol was proposed. This solution introduces a method that the calibration system can dynamically import address information of ECU variable based on MAP file generated by embedded development environment, and with this method, independence of calibration system and specific ECU application was accessible. The system integrates FLASH programming function and operator validation and authorization function by Seed&Key algorithm. An application example shows this system can calibrate ECU effectively. By timeconsuming modeling and CANbus status monitoring, influential factors of data transfer efficiency were analyzed, methods to improve communication efficiency were obtained and some basis for improving system realtime performance  were provided.