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 of 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.