Abstract: The polymer-flooding and combination-flooding as well as other tertiary oil extraction techniques have been widely used in Chinese oilfields in recent years.Although these techniques are able to enhance the oil recovery,more and more polyer-bearing wastewater as by product is thus fold increased per year,which leads to that the degradation of polymer-bearing oilfield wastewater plays a critical and difficult role in oilfield wastewater treatment.Due to the advantages of the ultrasonic degradation technique in strong oxidizing property,high degradation efficiency and no secondary pollution,more and more attention has been paid to its applications in wastewater treatment.In this article,the microscopic mechanism of the ultrasonic degradation technique and the characteristics of polymer-bearing oilfield wastewater are described.Also,further analysis is conducted about the polymer degradation mechanism of using ultrasonic irradiation for polymer-bearing oilfield wastewater and the demulsification mechanism of oil in water.Furthermore,the ultrasound degradation technique and the combined techniques in polymer-bearing both at home and abroad are summarized,in addition the future development trend of treating oilfield wastewater by ultrasonic irradiation is predicted.