Aiming at the problems of long dehydration time，large amount of demulsifier，and low dehydration efficiency of a certain heavy oil field in Xinjiang，a thermochemical sedimentation dehydration technology assisted by mixing super heavy oil with coking diesel oil was proposed. Experiments were carried out in the laboratory to reduce the viscosity of super heavy oil by adding different kinds of diluents at different temperatures，and the effect of the coking diesel oil extracted from super heavy oil on viscosity，cyclone desanding，demulsifier dosing concentration and dewatering was studied. The results showed that when blending coking diesel oil into the super heavy oil，the dehydration time of thermochemical sedimentation of super heavy oil was shortened and the concentration of demulsifier was reduced. When the second stage sedimentation tank was filled with super heavy oil blending with 9% coking diesel oil，the qualified water cut index of purification oil could be achieved as soon as the tank was full， and the average settling time of the second stage sedimentation tank filled with super heavy oil blending with 5% coking diesel oil was only 13.4 h，while the settling time before blending with coking diesel oil was 27.8 h. Moreover，the dosage of demulsifier SB-1 could be reduced to 100 mg/L after blending super heavy oil with coking diesel oil，which was 54.5% lower than that before blending，being of 220 m g/L. In addition，the addition of coking diesel oil could also enhance the swirling sand removal effect， reduce the viscosity of crude oil，end the history of on-site tank truck transport，achieve the long-distance pipeline gathering of super heavy oil，and reduce the cost by more than 40%.