The metering cylinders of the filling machine are respectively connected to the filling head, and the liquid of the main cylinder is reciprocated to suck a certain amount of liquid, and then injected into the container to be loaded. In this process, it is necessary to switch a through valve in time to change the flow direction of the liquid when the main cylinder is reversed. Moreover, during the injection process. In order to speed up the filling without causing the liquid to overflow, when filling 90% of the full bottle, a throttle valve connected in series in the injection path is opened to significantly reduce the injected flow rate. Then, the filled containers are sequentially removed, and the new empty containers are sequentially moved. During this process, the blocking plates installed at the inlet and outlet of the container are accurately and timely controlled to ensure that only the containers are moved in and out at a time. At the same time, make sure that the filling head can exactly match the mouth of the container, no matter which shape of the container is used. Otherwise, an alarm signal is output and the filling is not allowed to continue until the fault is not eliminated. Finally, the filling head can be accurately moved down after the container is in place to insert the filling into the bottle mouth. After the filling is completed, the filling head should be moved up quickly so that the container can be removed smoothly.