First heat up the crude oil to 90-130c through heat exchanger then add purified water and demulsifier, after mixing and then send in to electrical desalting and dewatering device to have the tiny droplets gradually extended to larger ,and then form a water layer to have water, dissolved salt, impurity ect removed. After desalting treatment, crude oil is heated up to 220-250c to enter in to pre-fractionator, light gasoline is extracted from top of pre-fractionator, topped crude from tower bottom through heat exchanger and atmospheric furnace to be heated up to 360-370 c, then enters in to atmospheric distillation tower, to separate out gasoline, kerosene ,light diesel, heavy diesel fractions, after electrochemical treatment, they’re product oil for supply. Atmospheric bottom heavy oil will be heated up to 380-400c and then flow in to vacuum distillation tower, to separate out different vacuum fractions, these fractions will be used as raw materials for catalytic treatment or lubricating oil. Vacuum residue after heat exchanged and cooled to be fuel or heat exchanged to make raw materials for coking, catalytic cracking, oxidation asphalt.