The multiple access protocol in data link will directly influence its performance and the weapon data link requires higher real time in message transmitting, so this paper presents a D-TDMA(Dynamic Time-Division Multiple Access) protocol supporting QoS(Quality of Service) in Weapon Data link network topology by ameliorating dynamic slots allocation algorithm, gives out the average end to end(ETE) delay formulae of different priorities traffic. A simulation model of weapon data link is created by OPNET, and then the influences on network time delay performance of different frame lengths are compared. The simulation results show that the D-TDMA scheme can meet the requirement of time delay, and provide high channel utilization in Weapon Data link communication.