The invention relates to an oil atmospheric vacuum distillation technology. An raw material inlet of a vacuum distillation tower and/or an atmospheric tower is connected with a tube side of a dividing-wall heat exchanger, a shell side inlet of the dividing-wall heat exchanger is connected with a molten salt heating furnace, a shell side outlet of the dividing-wall heat exchanger is connected with a molten bath, and the molten salt heating furnace is connected with the molten bath. Mixed inorganic salt powder-shaped particles are added in the molten bath, high-pressure steam or electricity is let in the molten bath, the mixed inorganic salt powder-shaped particles are molten to liquid, a molten salt circulating pump is started to carry out forced liquid phase cycles on molten salt when the melting temperature reaches 180 DEG C, the molten salt is transmitted to the molten salt heating furnace for heating, the temperature of the molten salt in the outlet of the molten salt furnace and the temperature of molten salt flow at the inlet of the dividing-wall heat exchanger are controlled between 350 DEG C to 530 DEG C, the molten salt is transmitted to the dividing-wall heat exchanger to heat oil flow to 360 DEG C to 440 DEG C and returns to the melting bath, and the oil flows from the dividing-wall heat exchanger and enters the atmospheric tower or the vacuum tower. According to the technology, the probability of green coke is low, the heating temperature can be improved, and the pull-out rate of the distillation towers can be increased.