There is no MARK point in the middle frame dispensing, but the dispensing area is small and the dispensing accuracy is high. With 2D positioning, only the shape feature points can be found for positioning. The traditional 2D positioning system relies on the color difference gradient of the feature points and the background to complete the positioning. With the diversification of products and social aesthetic changes, solid color products are gradually increasing, and traditional 2D positioning has been unable to adapt to changing process demands. At present, the common 3D positioning mode in the market is the laser line scanning mode, which has the disadvantages of high price and low efficiency.