Mobile Ad Hoc Networks(MANET) is a multi-ho Pand instant self-organized autonomous system of a collection of wireless mobile nodes.A multi-domain full-distributed Certification Authorities system model was proposed founding on its trait of territorial communication.The thesis researched this model and proposes a new model for the interoperability between virtual Certification Authorities named extended recommending trust model based on behavior.It can improve the system's security,retractility and robustness by dynamic trust chain maintenance with feedback information in the actual course.