Introducing Agent Techniques into the process of system integration will solve the problem about flexible dynamic system integration. The contract Net Protocol (CNP) has been applied to the negotiation in Multi-Agent System. On the basis of the research on traditional CNP, by improving its ability to deal with dynamic environment, this paper presents a Contract Net Model based on Agent Active Perception (CNMAAP) to improve the efficiency of negotiation. With the introduction of a perception coefficient and a parameter for the degree of credibility to CNMAAP, the paper puts forward the tendering strategy for contract manager and the bidding strategy for contract tender, after which an analysis of the efficiency of CNMAAP is made. Finally, CNMAAP is applied to the Agent-based System Integration Tool, and has been tested with the Border and Coast Defense Simulation System. The result demonstrates that, compared with traditional CNP, CNMAAP can effectively reduce the negotiation cost with assured quality.