In Delay-Tolerant Network(DTN), certain malicious node might generate congestion in attack to reduce the overall performance of the whole network, especially the target of message successful delivery ratio. In this paper, a novel Nash equilibrium based congestion control routing algorithm with the function of security defense (NESD) is proposed. In the process of message delivery, node can use Nash equilibrium to compute the largest proportion of transfer messages occupancy to node memory capacity. This mechanism constrains the attack from malicious node and guarantees the message transfer of regular node. This congestion control routing algorithm for security defense is evaluated by experiment. It is important application in the field of homeland defense. The results show that related key parameters are significantly improved in DTN scenario.