Abstract: This paper studies and designs a multi-channel MAC protocol based on TDMA.In order to improve the utilization ratio of resource as far as possible, this protocol could change the length of the subframe dynamically and make control channel and data channels overlap in the time domain.The negotiation mechanism is adopted to reduce the packet conflict effectively, ensure the network throughput and delay.By modeling in the OPNET simulation platform, when the network load traffic is high, the packet transmission success rate and low latency can be guaranteed to provide reference for the design of Ad Hoc network.