Si/SiC hybrid switch offers an effective tradeoff between cost and performance, but suffers from complex switching processes and limited analytical theory. It is highly desirable to build a complete behavior model to investigate and characterize switching behavior for Si/SiC hybrid switch. In this paper, a Finite State Machine(FSM) based modeling method is proposed to analyze the switching behavior of Si/SiC hybrid switch. Based on the principle of circuit equivalence, the switching transient of the gate-controlled power device is innovatively divided into Voltage Source Mode(VSM) and Current Source Mode(CSM). The behavior model is developed with full consideration circuit stray parameters and is verified by a double-pulse test, which exhibits excellent validity. Furthermore, the proposed method not only provides a reference for switching behavior analysis and loss prediction of Si/SiC hybrid switches, but also can be applied to multiple devices in parallel which means it has excellent extensibility performance.