The sensor-weapon joint task management under dynamic environment was studied. The stage threshold, which determines the beginning of next stage, was set according to the number of valid newly appearing targets, idle sensors and weapons during the dynamic combat process. The multi-stage combat process was constructed. The effect of distributed combat system to the quality of attack scheme and the response time of system was analyzed. As a result the system could decide the response flow of each task management stage independently. The superiority of constructing distributed combat system and setting the stage threshold was verified by simulations.