The pepper dryer distributes the materials to be processed on the conveyor belt through an appropriate spreading mechanism, such as a star-shaped distributor, a swinging belt, a pulverizer or a granulator. The conveyor belt passes through a channel composed of one or more heating units, each of which is equipped with an air heating and circulation system, and each channel has one or more moisture removal systems. When the conveyor belt passes through, 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 made.