According to the current situation and problem of partial ventilator operation, based on PLC technology and frequency conversion technology, underground partial ventilator along with the gas concentration automatic adjustment system, based on the needs of production field, Siemens S7-200 series PLC, KG9701 intelligent low concentration gas sensors and Siemens MM430 frequency converter were adopted to realize automatic control and alarm and partial ventilator, start the standby blower and ensure the safe production.