The metering and distribution machine realizes the control of fast, medium and slow valve closure, and the cylinder stroke is controlled by PLC signal to complete the actions of weighing, filling, opening, opening, closing and capping. When the weighing module reaches the given weight value, the opening cylinder returns to the filling valve and closes the opening cylinder to move to the given position, the opening cylinder moves upward, and the valve cover is installed. By driving a piston through the cylinder to draw and pump out the material, the flow direction of the material is controlled by the check valve, the stroke of the cylinder is controlled by the magnetic spring switch to adjust the filling amount, the weighing module is connected with the data line of the weighing instrument, and the pressure signal of the electronic scale is continuously transmitted to the weighing instrument during the measurement process, and the control instrument controls the pump and closes the pneumatic valve when the preset quantitative weight is reached.