Control method and control device

A control method and a control device (100). The control device (100) is connected to an external load (200), and comprises: a power module (120); a microcontroller unit (110) for receiving an input command, a power control output terminal (c1) of the microcontroller unit (110) being connected to a control input terminal (o2) of the power module (120); a control circuit (130), a signal input terminal (s2) of the control circuit (130) being connected to a signal output terminal (c2) of the microcontroller unit (110); and a relay (140) having a contact, a power input terminal (p0) of the relay (140) being connected to a power output terminal (o1) of the power module (120), a control input terminal (p1) of the relay (140) being connected to a signal output terminal (s3) of the control circuit (130), a signal output terminal (p2) of the relay (14) being connected to an input terminal (m1) of the external load (200), a control signal of the control input terminal (p1) controlling the contact to be closed or opened, and the signal output terminal (p2) of the relay (140) outputting a state control signal to the external load (200) when the contact is closed, wherein a level conversion circuit (150) is further provided between the microcontroller unit (110) and the control circuit (130), a signal input terminal (v1) of the level conversion circuit (150) is connected to the signal output terminal (c2) of the microcontroller unit (110), and a pulse output terminal (v2) of the level conversion circuit (150) is connected to the signal input terminal (s2) of the control circuit (130).