Backwards-flowing preventing device of region sewage system

The utility model provides a backwards-flowing preventing device of a region sewage system, belonging to the technical field of sewage discharge equipment. The technical scheme is as follows: a liquid level meter (1) is fixed on a sewage buffer box (9), and is connected with a control box (8) through a signal cable, two sides of the sewage buffer box (9) are respectively communicated with a sewage inlet pipe (7) and a municipal sewage pipe network guiding pipe (4), one end of a lifting screw rod (2) is connected to a sewage buffer box body, the other end of the lifting screw rod is connected with a backwards-flowing preventing sluice gate (3), the backwards-flowing preventing sluice gate is positioned at a pipe opening of the municipal sewage pipe network guiding pipe in the sewage buffer box (9), the size and the up-down moving distance of the backwards-flowing preventing sluice gate are both matched with the diameter of the municipal sewage pipe network guiding pipe, an outlet of a sewage cutting pump (6) i