Abstract: With the using conditions and working environment become more and more severe, the rate and bandwidth do not meet the requirements of traditional CAN bus, CAN FD bus arises at the historic moment.But the sending rate of CAN FD bus influenced by its delay, must use the transmission delay compensation mechanism.The paper analyses the reasons of the limited transmission speed, and put forward a kind of automatic transmission delay compensation method, whichimplemented in independently developed controller.The controller can flexibly turns on the compensation mechanism through real-time message, which can dynamically locate the position of the secondary sample points and ultimately improve the stability and flexibility of the controller.