The work aims to design a new automatic weighing system of the packaging machine to complete weighing and packaging quickly, with the increasing demand for bagged goods. A packaging machine control system based on the ARM minimum system was designed, which included the weighing structure of 2 mV/V double strain gauge, the DAC conversion circuit and the driving circuit of the mV level. Moreover, the weight acquisition and response comparison experiment were finally used to analyze the system by programming the software systems like weighing process, AD device driver and wavelet transform extraction. Based on the experiment, the weight that could be stably identified was 300 g when the wavelet transform extraction signal was at 0.2 ms. The results show that the designed automatic packaging system can achieve the fast and stable weighing and packaging of all kinds of bagged products.