Abstract—At present, the sample analysis and detection process in many field such as food and medicine is spent most of the time on the sample preprocessing step. In order to improve the detection efficiency and reduce the preprocessing error, a sample preprocessing platform based on the dissolution method was designed, and its automation and control system were analyzed in detail. The platform automatically prepares solutions, handles batch samples, and ultrasonically extracts mixed solvents. The human-computer interaction interface and software system are designed based on PC and PLC for distributed control of valves, syringe pumps and three-dimensional motion mechanisms. The platform has high degree of automation and wide range of application, and solves the shortcomings of labor force, low efficiency and wide error source brought by manual preparation of solution.