Abstract: As an important MAC layer access control protocol, CSMA/CD protocol is widely used in industrial control network. The model of CSMA/CD and binary exponential backoff algorithm is analyzed, and CSMA/CD protocol is simulated using MATLAB, in view of the difficulty found among students in understanding the principle of network protocol. The performance of the binary exponential backoff algorithm is analyzed through Markov model, and the theoretical throughput of CSMA/CD is derived. Under the MATLAB environment, the throughput of channel versus user node number, physical layer data rate is simulated. Simulation results show that the channel utilization rate is lower; the user number of nodes is larger and physical layer rate is higher due to the inter-frame slot and the network loopback time constraints.