Precise disinfectant metering device

The utility model discloses a precise disinfectant metering device. The precise disinfectant metering device comprises a metering cylinder, a threaded hole formed in the middle of a top plate of the metering cylinder is internally in threaded connection with a threaded cylinder, a clamping groove is formed in the outer arc face of the threaded cylinder, the upper surface of the metering cylinder is rotationally connected with a drive plate, the threaded cylinder penetrates through a round hole formed in the center of the drive plate, and a clamping block arranged on the inner arc face of the round hole of the drive plate is in sliding connection with the inner wall of the clamping groove. A piston is arranged at the bottom end of the connecting column and slidably connected with the inner wall of the metering cylinder, the lower surface of the threaded cylinder makes contact with the upper surface of the piston, scale marks are arranged on the left side of the outer arc face of the connecting column, the oute