Suction-back type high-precision dispensing valve

The utility model discloses a back-suction type high-precision glue dispensing valve, which comprises a fixed seat, a motor, a screw rod, a glue barrel, a movable block, a piston and a deformation piece, the motor and the glue barrel are respectively arranged at two ends of the fixed seat, one end of the glue barrel is provided with a glue outlet, the movable block is slidably arranged in the fixed seat and is slidably connected with the glue barrel, and the piston is arranged at one end of the movable block. The motor drives the lead screw to rotate, so that the piston is driven by the movable block to move in the glue barrel, accurate glue discharging is achieved, the first channel and the second channel are communicated with the deformation piece, the deformation piece is arranged at the end, away from the movable block, of the piston, and the lead screw is rotationally arranged in the fixed seat and connected with the motor in a screwed mode. When glue discharging is stopped, the negative pressure in the