The present disclosure relates to a fan drive system and a fan. The fan drive system comprises an AC power supply, a filter unit, a rectifier unit, a bus capacitor, a switching power supply, a bus voltage isolation detection circuit and a DC motor drive unit. Wherein a speed regulation switch is provided between the AC power supply and the filter unit having an output end connected to an input end of the rectifier unit with an output end connected to an input end of the switching power supply. The circuit is configured to detect voltages at two ends of the bus capacitor, an output end of the switching power supply is connected to the DC motor drive unit for supplying power, and an output end of the circuit is connected to the DC motor drive unit for inputting speed regulation signals. The DC motor drive unit is connected to a DC motor for driving the DC motor.