The invention relates to a feeding device used for conveying material boxes containing materials. The feeding device comprises a machine frame, an input mechanism and two positioning mechanisms. The input mechanism is used for inputting the material boxes and arranged on the machine frame, and comprises a feeding chain and a feeding drive motor connected with the feeding chain. The material boxes are arranged on the feeding chain. The feeding drive motor drives the feeding chain to move so as to drive the material boxes to move. The two positioning mechanisms are arranged on the machine frame. Each positioning mechanism comprises a supporting frame, a material box receiving assembly and a positioning assembly. The supporting frames are fixed to the machine frame. The material box receiving assemblies and the positioning assemblies are arranged on the supporting frames. The material box receiving assemblies can receive the material boxes conveyed by the input mechanism. The material boxes can be positioned through the positioning assemblies. By means of the feeding device, the material boxes can be automatically and accurately positioned so that a mechanical arm can accurately grab the materials in the material boxes, automatic production is achieved, and the production efficiency and the product quality are improved.