The invention provides an automatic filling machine. The automatic filling machine comprises a machine frame. A material storage box is arranged on the machine frame. A conveying device used for conveying containers is arranged on the machine frame. The automatic filling machine further comprises a weighing device. The weighing device is arranged at the position, located at the lower end of the conveying device, of the machine frame. A filing machine body is further arranged on the machine frame and communicates with the material storage box through a discharging pipe. A speed control gear pump is arranged on the discharging pipe. The filling machine body is provided with a filling discharging outlet. An electric valve is arranged at the filling discharging outlet and provided with a signal receiving processor. The signal receiving processor is electrically connected with the electric valve. The problem that liquid spills from the containers or filling ports cannot be aligned to container openings when filling machines on the market today are used for filling is solved. Through the automatic filling machine, the filling flow and flow rate can be well controlled, the practicabilityis high, and the working efficiency is high.