Tailings flocculation and sedimentation experiment is the basis of tailings thickening process, and it is also a necessary link to determine the production parameters and equipment selection of thickener. Based on image processing technology, a set of observation and intelligent analysis system for tailings flocculation and sedimentation was independently developed. The system used an industrial camera to collect the experimental images of tailings flocculation and sedimentation. Using gray processing, Gaussian filtering, image segmentation and other methods, the position of solid-liquid separation interface in the process of tailings flocculation and sedimentation can be intelligently identified by measuring the area and coordinate attributes of the region; Taking Dongguashan copper tailings as experimental materials, the tailings flocculation and sedimentation experiment was carried out using this system and the change law of tailings settlement curves was explored. Considering the changes of sedimentation velocity at the separation interface, turbidity of supernatant, static limit sedimentation concentration and solid flux, the optimal process production parameters were determined; According to Kynch settlement theory, the settlement process curves were further analyzed and the settlement parameters were calculated. Based on the actual production capacity of the mine, the key parameters such as thickener diameter and height were intelligently recommended for the mine.