Removal of water contained in extra-viscous crude oil is quite difficult because of the high viscosity and high resins content of heavy oil.The microwave technology was introduced for the separation of water from high-viscosity crude oil in the presence of sodium acetate.The decrease in zeta-potential of interface and the viscosity of crude oil are responsible for the accelerated separation of water under microwave irradiation.The influences of the concentration of sodium acetate in sample,irradiation pressure,irradiation time and irradiation power on the separation efficiency were investigated.The optimum technological condition for the refining process was determined.Upon treating the sample 1 (with a water concentration of 50％),the water removal rate was 98.44％,when the optimum conditions were identified to be a sodium acetate concentration of 2％,an irradiation pressure of 0.1 MPa,an irradiation time of 2 min,and an irradiation power of 225 W,with the recovery of sodium acetate reaching 97.88％.Upon treating the sample 2 (the concentration of water was 20％),the water removal rate was 93.85％,when the optimum conditions were determined to be a sodium acetate concentration of 3％,an irradiation pressure of 0.1 M Pa,an irradiation time of 4 min,and an irradiation power of 375 W,with the recovery of sodium acetate reaching 93.54％.By using this method,the dehydration efficiency was increased rapidly.