An automatic quantitative weighing system of granular propellant is developed to meet the requirement of automatic quantitative weighing during the granular propellant packaging process. Firstly, the devices of this system are introduced. Then the design and implementation of control system are explained in detail. Finally, the automatic feeding and quantitative weighing has been achieved by researching vacuum conveying technology and electronic quantitative weighing technology. The system has been applied in production, the application results show： the system can package 80 containers per hour, it realizes automatic feeding, quantitative weighing and charging, imoroves the quality and safety of packaging.