A control method of an electromagnetic clutch in a hybrid power system, the hybrid power system comprises an engine or motor, a motor, an electromagnetic clutch, an electromagnetic clutch controller and a power supply system; the power supply system comprises a low-voltage battery, a standby power supply system and a switching circuit, the low-voltage battery is used to supply power to the electromagnetic clutch controller and the electromagnetic clutch, and the electromagnetic clutch is used to control connection of the motor, the control method specifically comprises the following steps: step 1, monitoring whether a voltage of the low-voltage battery is lower than a target value, and determining that the low-voltage battery fails when the voltage of the low-voltage battery is lower than the target value; step 2, when the low-voltage battery fails, using the switching circuit to switch to the standby power supply system to supply power to the electromagnetic clutch and the electromagnetic clutch controller; step 3, using the electromagnetic clutch controller to judge an engaged or disengaged state of the electromagnetic clutch; and step 4, further controlling the electromagnetic clutch, by the electromagnetic clutch controller, according to the engaged or disengaged state, to make the electromagnetic clutch in the engaged state until a power supply fault is eliminated; characterized in that: the step 4 specifically comprises: when the electromagnetic clutch is in the engaged state, maintaining the engaged state; when the electromagnetic clutch is in the disengaged state, judging whether it is necessary to send a command of electromagnetic clutch engagement according to a vehicle speed signal; judging whether it is necessary to send the command of electromagnetic clutch engagement according to the vehicle speed signal comprises: judging whether the vehicle speed signal can be detected; if the vehicle speed signal can be detected, judging whether it is necessary to send the command of electromagnetic clutch engagement according to a vehicle speed; when the vehicle speed signal cannot be detected, sending the command of electromagnetic clutch engagement after a preset time period. step 1, monitoring whether a voltage of the low-voltage battery is lower than a target value, and determining that the low-voltage battery fails when the voltage of the low-voltage battery is lower than the target value; step 2, when the low-voltage battery fails, using the switching circuit to switch to the standby power supply system to supply power to the electromagnetic clutch and the electromagnetic clutch controller; step 3, using the electromagnetic clutch controller to judge an engaged or disengaged state of the electromagnetic clutch; and step 4, further controlling the electromagnetic clutch, by the electromagnetic clutch controller, according to the engaged or disengaged state, to make the electromagnetic clutch in the engaged state until a power supply fault is eliminated; characterized in that: the step 4 specifically comprises: when the electromagnetic clutch is in the engaged state, maintaining the engaged state; when the electromagnetic clutch is in the disengaged state, judging whether it is necessary to send a command of electromagnetic clutch engagement according to a vehicle speed signal; judging whether it is necessary to send the command of electromagnetic clutch engagement according to the vehicle speed signal comprises: judging whether the vehicle speed signal can be detected; if the vehicle speed signal can be detected, judging whether it is necessary to send the command of electromagnetic clutch engagement according to a vehicle speed; when the vehicle speed signal cannot be detected, sending the command of electromagnetic clutch engagement after a preset time period. when the electromagnetic clutch is in the engaged state, maintaining the engaged state; when the electromagnetic clutch is in the disengaged state, judging whether it is necessary to send a command of electromagnetic clutch engagement according to a vehicle speed signal; judging whether it is necessary to send the command of electromagnetic clutch engagement according to the vehicle speed signal comprises: judging whether the vehicle speed signal can be detected; if the vehicle speed signal can be detected, judging whether it is necessary to send the command of electromagnetic clutch engagement according to a vehicle speed; when the vehicle speed signal cannot be detected, sending the command of electromagnetic clutch engagement after a preset time period. judging whether the vehicle speed signal can be detected; if the vehicle speed signal can be detected, judging whether it is necessary to send the command of electromagnetic clutch engagement according to a vehicle speed; when the vehicle speed signal cannot be detected, sending the command of electromagnetic clutch engagement after a preset time period.