Hexane refining system and method based on production of high-density polyethylene

The invention discloses a hexane refining system based on production of high-density polyethylene. The hexane refining system comprises a preheater, wherein the preheater is connected with a mother liquor separation tank, the mother liquor separation tank is connected with a condenser, the condenser is connected with a hexane feeding tank, the hexane feeding tank is connected with a rectifying tower, the top of the rectifying tower is connected with a tower top condenser, the tower top condenser is connected with a collecting tank, the collecting tank is connected with a rectifying tower, thebottom of the rectifying tower is connected with a cooler, and the cooler is connected with a hexane absorption tower. The invention also discloses a hexane refining method. The method specifically comprises the following steps: adding an inactivator into mother liquor to inactivate substances in the mother liquor; discharging most of a reaction product and the excessive inactivator from the bottom of an evaporator togeth