In view of the characteristics of dynamic, openness and complexity, this makes aerospace network high in security .To make full use of prior knowledge, the neural network theory should be used to build up a model of the trust. Through the establishment of acquaintance community, recommending trust value is obtained. Lastly, the problem of malice recommendation is solved by BP neural network with penalty. The model proposed in this paper provides a new way for studying behavior trust in Aerospace Network.