This paper presents a novel method of structural synthesis and analysis of hybrid mechanisms based on the set theory. The basic concept of GF set, algorithms and the type synthesis principle based on GF set are firstly introduced. The topological arrangements of hybrid mechanisms can be developed by the elements of GF set combination and rotation axis transfer theorem to obtain the multi-loop forms of hybrid mechanism. According to the approach proposed in this paper, 3T2R 5-DoF hybrid mechanism with determined kinematic characteristic is enumerated. Meanwhile, a method is proposed to analyze kinematic characteristic of hybrid mechanisms synthesized above. Finally, a novel hybrid mechanism is synthesized to demonstrate the applicability of the novel method of structural synthesis for hybrid mechanisms.