A method and device for adjusting the switching speed of a MOSFET are disclosed. The MOSFET is connected to drive switch, the collector of the drive switch is connected to the grid of the MOSFET through the grid resistor, the emitter of the drive switch is grounded through the emitter resistor, and the collector of the drive switch is also connected to the source resistor through the collector resistor, the other end of the source resistor is connected to the source of the MOSFET; the drain of the MOSFET is connected to the current source. The method comprises: obtaining the adjustment target of the switching speed for the MOSFET, determining the first resistance value of the emitter resistor and/or the second resistance value of the collector resistor based on said adjustment target, controlling the operation of the MOSFET according to the adjusted resistance value.