Negative-pressure weighing room

The invention discloses a negative-pressure weighing room. The negative-pressure weighing room comprises an outer box body, as well as an air return box body, an air supply box body and a working space which are arranged in the outer box body, wherein the air supply box body is arranged at the inner upper part of the outer box body; the air return box body is arranged on one side below the air supply box body in the outer box body, and the air supply box body, the air return box body and the outer box body surround the working space; a blower support and an air feeder on the blower support are both arranged in the air return box body, and the air outlet of the air feeder is led into the air supply box body; a primary filter and an intermediate-acting filter are arranged in the air return box body to filter air entering the air return box body; an efficient filter is arranged on the air supply box body and corresponds to the junction of the air supply box body and the working space, an air outlet is formed in the lower side surface of the air supply box body, adjacent to the working space, and a flow equalization membrane is arranged on the air outlet. The negative-pressure weighing room enables the working space to generate negative pressure, prevents cross contamination, ensures safety of an operator, avoids secondary contamination caused by weighing and ensures high-cleanliness environment of the working space.