The chili dryer distributes the materials to be processed on the conveyor belt through appropriate spreading mechanism, such as star fabricator, swing belt, crusher or granulator, the conveyor belt passes through the passages composed of one or several heating units, each of which is equipped with air heating and circulating system, and each of which has one or several humidity draining systems, and when the conveyor belt passes through, the hot air is passed through the materials on the conveyor belt from the top to bottom or vice versa, so that the materials can be dried uniformly. When the conveyor belt passes through, the hot air passes through the materials on the conveyor belt from top to bottom or from bottom to top, so that the materials can be dried evenly.