The utility model discloses a liquid filling system, which relates to the technical field of automation and comprises a controller, a recognizer and a filling device. The controller is respectively connected with the recognizer and the filling device; the recognizer recognizes the model of a workpiece and sends the model of the workpiece to the controller, and the controller determines the injection amount according to the model of the workpiece and transmits the injection amount to the injector. And the filling device is used for filling liquid into the workpiece according to the filling amount. The embodiment of the utility model aims to provide the liquid filling system, the operation process is simplified, the risks of missing filling and mistaken filling during liquid filling are reduced, and the quality cost and the labor cost are reduced.