The invention relates to a fan control circuit, which is used for controlling a fan to supply radiated heat to electronic equipment and comprises a comparator and an electronic switch. An in-phase input end of the comparator receives working current of the electronic equipment and is connected with a first power source through a first resistor, while a phase-reversing input end is connected with the power source through a second resistor and is earthed through a third resistor; a first end of the electronic switch is connected with the output end of the comparator, a second end of the electronic switch is earthed, and a third end of the electronic switch is connected with a second power source through a fourth resistor; the fan is connected between the second end and the third end of the electronic switch; the comparator compares the voltage at the in-phase input end with the voltage at the phase-reversing output end, then outputs a control signal to control the on-off of the electronic switch, thereby controlling the fan to work when the electronic equipment is in an operating state and stop working when the electronic equipment is in a standby state. The fan control circuit has simple structure and lower cost.