The work aims to design an embedded control system based on ARM microcontroller for the purpose of improving the control precision, real-time and system integration of bag-making machine. The working principle of bag-making machine was described in detail. The packaging bag was made from film through feeding, traction, heat sealing and cutting process. The hardware design method was given, including controller, sensor module and electric execution module. Meanwhile, the servo motor speed control and tension floating roll control algorithms were discussed. The software design method was given based on uC/OS-II. The control system described had advantages such as high integration level, good real time, low development cost and so on. The control system can meet the technological requirements and control requirements of bag-making machines.