To solve the problems of updating, modifying, upgrading and maintaining the function of robot by offline and static method, SoftMan was introduced for robot platform, and the architecture of robot system, whose managing center is host SoftMan, was built. The host SoftMan was mainly researched. Firstly, the architecture of host SoftMan was constructed. Then the descriptive unification model of knowledge and behavior of host SoftMan was put forward, the knowledge model was constructed and implemented based on data structure, and the design specifications and reference realization of the algorithm were given for its main service behaviors. Finally, the robot system was unified with the SoftMan system. Through the test, the function of robot was successfully replaced online and dynamically, verifying the correctness and feasibility of the method of designing and implementing the host SoftMan.