The combined three-phase separator adopts several new technologies such as pre-degassing of liquid swirl,water washing and demulsification,efficient coalescence and oil-water liquid level control,so that the water-bearing crude  oil can reach the standard of qualified crude oil after one treatment,and the   equipment has the characteristics of compact structure,large processing capacity,stable and reliable operation and control,clear functions of each part,high effective utilization rate,good separation effect and high degree of automation.Its unit volume processing capacity is 6~8 times that of traditional equipment,for the general high water content crude oil,the dehydration rate is 99%,the water content of water content of water crude oil is<1%,and the oil content of sewage is<1000mgl.