Unmanned ground vehicle swarm was proposed to monitor the process of reentry vehicle landing, and then the techniques about intelligent swarm self-organizing strategy were researched. Swarm behavior patterns about unmanned vehicle swarm collaboratively monitoring the process of reentry vehicle landing were designed and the swarm self-organizing strategy based on cooperative game was presented for the swarm aggregation behavior in the process of collaborative monitoring. Each agent regards achieving swarm aggregation and saving energy as top goal and carries out the gaming. The particle swarm optimization was used to program the local path thus the aggregation behavior was realized. Simulation experiment proves the effectiveness of the autonomous aggregation strategy.