Study on Authentication Protocol of SDN Trusted Domain Currently Software Define Network (SDN) architecture has become a hot topic. Aiming at the authentication security issues of SDN network architecture, we introduce an authentication protocolbased on SDN network architecture without any trusted third party between trusted domains. By applying AVISPA security analysis system of network interaction protocol, we can guarantee protocolsecurity and provide complete safety tests. Our work fill the gap of mutual trust between different trusted domains and provide security foundation for interaction between different trusted domains.