The invention provides a material grouping mechanism which comprises a frame and at least two sliding blocks. The sliding blocks are slidably arranged on the frame. A telescopic device is connected between the two sliding blocks or between one sliding block and the frame. Each sliding block is provided with a material gripping device which is used for gripping materials from a conveyer belt. The sliding blocks can slide on the frame to drive the material gripping devices on the sliding blocks to slide, so the positions of the material gripping devices can be adjusted, and the material grouping mechanism can adapt to transporting of the materials with different sizes and improves adaptability. The telescopic device plays a role in transmitting moment in the process of position adjusting and moving of the sliding blocks. Just the moment is exerted on the sliding blocks at two ends, and the other sliding blocks can be driven to slide under the action of the telescopic devices. Through adjustment of the exerted moment, the distances between the materials can correspond to the sizes of the materials. Consequently, the material grouping mechanism achieves transporting and packaging of the materials with the different sizes, improves efficiency and saves cost.