Aiming at the disadvantages, such as low precision, poor quality and low safety in the traditional process, an automatic control system for certain type composite processing of a fixed propellant was designed. This paper analyzes the traditional process of propellant processing, puts forward the research content and design points, completes the construction of hardware platform framework, and has been applied in the actual project. The verification results show that the system realizes the automation of propellant composite processing and has the advantage of short design cycle.