The utility model provides an improve device that rises film evaporator vapor -liquid separation effect includes reboiler, gas liquid separator, overhead condenser, the lower extreme at gas liquid separator is connected to the reboiler, and establish in the gas liquid separator upper end overhead condenser part, and gas -phase pipe establishes at the overhead condenser upper surface, just communicates with gas liquid separator, and the fraction discharging pipe is established at the overhead condenser lower surface, is just communicate with gas liquid separator. The utility model discloses the advantage lies in, can promote the separation effect and prolong equipment cycle of operation.