In oil and gas processing station, the regenerative adsorption dryer absorbs the compressed air moisture to ensure the dew point of the gas. Once the dryer fails, it will cause the water dew point to rise, which will affect the operation parameters of the device in winter when the automatic control valves freeze. Control valves freezing can lead to serious consequences such as release, gas-Migration, and unqualified product quality and so on, which are difficult to deal with. The pressure of dryer and regenerative pressure are characterized by a certain periodic change when dryer is working. This paper introduces the automatic identification technology of the dryer fault. Logic analysis through DCS system can identify faults by analyzing the time curve of regenerative pressure, catching abnormal changes of the curve during the failure of dryer. The automatic identification technology of the dryer fault will be achieved in a short time and send out alarm signal to ensure the safe operation of the oil and gas treatment station. It is highly valuable for wide extension and application.