A systematic and effective type synthesis method was proposed for five degrees of freedom (DoF) hybrid mechanisms based on the linear dependency of screws and units of the lowermobility SKM with singleopenedchain limb, including the definition and symbol denotation method of both hybrid robot with a parallel mechanism and multiparallel mechanisms. Type synthesis of 5DoF SKMs with singleopenedchain was classified based on the screw theory. Based on the principle of freedom of assignment, the type synthesis of hybrid mechanisms were accomplished by regarding PKM as a complex kinematic unit and replacing an equal DoF kinemtic chain limb in lowermobility SKM with singleopenedchain limb. Other type synthesizes of hybrid mechanisms were generated by the linear combination of the twist and the correctness of the configuration was verified by an example. This kind of mechanisms has the advantages of series mechanisms and parallel mechanisms, and has certain application prospect.