The invention discloses a control method of an automatic material charging bag applicator. The control method is characterized in that the material charging bag applicator is adopted to pick up and open a packaging bag, the packaging bag is transversely placed on a bag placing tray of an X-axis conveying device for conveying, the X-axis conveying device conveys the packaging bag to an operation station of a remaining bag supporting mechanism, and a remaining bag tray of a Y-axis supporting device moves outwards in the Y-axis direction and is connected into the bottom of the packaging bag in aninserting mode; and the packaging bag is transversely placed on the remaining bag tray of the Y-axis supporting device, a guide suction bag mechanism is used for upwards lifting the side edge of thepackaging bag, a bag taking device of a bag grabbing mechanical arm clamps the side edge of the lifted packaging bag, and a bag opening device is used for adsorbing and opening the opening of the packaging bag so as to enable the packaging bag to receive materials. According to the control method of the automatic material charging bag applicator, conveying, bag taking and bag opening of the packaging bag are effectively achieved, the working efficiency is improved, and relatively good practicability is achieved.