In UAV Ad Hoc networksmulti-priority services are transmitted in parallel,and the existing mechanism of channel busy/idle state division does not consider the fuzzy characteristics of channel states.To solve the problema probabilistic media access control protocol based on fuzzy division of channel busy/idle state is proposed.The protocol mainly adopts two core mechanismsthat isfuzzy division of channel busy/idle state and media access based on probability.The former mechanism can more reasonably divide the channel busy/idle degree by analyzing the fuzzy characteristics of channel states.The latter mechanism can improve the successful transmission rate of the highest priority services and channel utilization rate while effectively reducing data packet collisions under heavy network load.The simulation results show that the protocol can realize the differentiated transmission of multi-priority servicesprovide strict timeliness and reliability for the transmission of the highest priority serviceand improve channel utilization rates under heavy network load.