The invention discloses an SDH equipment fan control device and method and is applied to SDH optical transmission equipment in a communication system to realize SDH optical transmission equipment temperature detection and fan control. The device comprises a device body used for being inserted into a slot of SDH optical transmission equipment, wherein a fan, a heater and a core controller are mounted on the device body, a side surface of the device body is provided with a power supply module, an external fan power supply interface with a fan of the device, a switch and a heat dissipation hole,the core controller is in circuit connection with the heater, the fan and the external fan power supply interface through a relay module, the power supply module is electrically connected with the core controller through the switch, and the core controller is integrated with a temperature control sensor.