The parasitic inductance scattered across the gate, source, and drain of the metal-oxide-semiconductor field-effect transistor (MOSFET) changes the switching characteristics of the MOSFET due to the packaging and printed circuit board (PCB) wiring. Through simulation analysis and comparison, it is pointed out that MOSFET parasitic inductance has the following characteristics. The source inductance forms a negative feedback on the gate drive, resulting in a slow switching speed. The Kelvin connection can decouple the gate loop and the power loop and quicken the driving speed. When the Miller effect occurs, the gate inductance should be reasonably reduced to reduce the driving current of the gate. The drain inductance influences the switching speed of MOSFET through Miller capacitance, resulting in an increase in voltage stress at the turn-off moment. In the parallel circuit, the asymmetrical layout will lead to the dynamic uneven current between MOSFETs. When the loop inductance oscillates with the junction capacitance of MOSFET in the switching process, the loop inductance can be reduced by adding the absorption capacitance in the circuit, and the oscillation characteristics can be changed.