Recommendations: Select demulsifier and determine dosage by small batch test in laboratory 1.Take 100ml of raw waste water, add the corresponding amount of demulsifier and stir it for 10S. 2. Add PH valueregulator to make raw water PH value to be 7-9, and continue to stir for 10S. 3.Add the coagulant (polyacrylamide) aqueous solution to accelerate flocculation,stir it for 15S, and wait for the precipitation to finish; 4. Increase or decrease demusification dosage according to the demulsification effect of raw wate to determine finial minimum dosage.