The invention discloses a crude separation system and a crude separation method for cumene method epoxidation products. The separation system comprises an alkaline washing tower, a crude PO tower, a dividing wall tower, a flash tower, an extraction tower and an oil-water separation tower, wherein the alkaline washing tower and the crude PO tower are combined into a superposition tower; the flash tower, the extraction tower and the oil-water separation tower are combined into a superposition tower, and the dividing wall tower is provided with a dividing wall in the middle; and by adopting the dividing wall tower and superposition tower technology, the occupied area of the equipment is reduced by 16.67-44.44%. According to the separation method, low-pressure steam is injected into the crude PO tower to reduce the temperature of a tower kettle, so that the temperature of the tower kettle is reduced to 85-110 DEG C, the increment of cumene is reduced to 6.8-8.6 wt%, the loss of cumene is reduced to 0.11-0.13 kg CUM/tPO, the problems of large occupied area of equipment and large loss of cumene in the prior art are well solved, and the separation method can be applied to 50000-900000 tons of CHPPO devices for producing PO.