Directional ad hoc networks offer advantages of farreaching propagation distance, large antenna gain, and space reusability. Due to the strong directionality of directional antennas, it is impossible to perceive omnidirectional information and the channel environment cannot be predicted. Therefore, finding neighboring nodes is challenging. It is of great significance to study directional ad hoc networks and use their advantages to overcome their shortcomings. This paper analyzes two problems in directional ad hoc networks, namely, the link collision problem and the link starvation problem. To address these issues, this paper proposes a multi-channel multiple access protocol based on classified time slots. First, it analyzes the relationships between these two issues. Second, it puts forth the basic idea of the protocol. Next, the system model is shown. The agreement is specifically described at length. It is partitioned into three periods: a scanning phase for neighbor discovery and for selecting reserved resources, a reservation phase for data resource reservation, and a data transmission phase. Simulation results showed that the protocol not only can increase the network throughput, which increases by an average of 25% when the node number is small and 5-fold when the node number is large, but also can improve the fairness of the network, with an average increase of 32% when the number of nodes is small and an average increase of 5-fold when the number of nodes is large.