The work aims to design a high-precision control system for weighing and packaging, in order to improve the packaging speed and accuracy of quantitative weighing packaging machine. The mechanical structure and working principle of quantitative weighing packaging machine were introduced. According to this, a kind of DSP-based touch-screen quantitative weighing packaging control system was designed, and the hardware structure based on DSP and touch screen was described in detail. Finally, on the basis of hardware structure, the control system software for quantitative weighing and packaging was developed. The experimental results showed that the maximum relative error of weighing and packaging was no more than ±0.6%. The control system improves the accuracy, reliability and operability of the quantitative weighing packaging machine.