The invention provides a three-layer oven applicable to restaurants, dining halls, homes and the like. The three-layer oven comprises an oven body, heat dissipation air holes, a heat preservation layer, an unfreezing layer, a disinfecting and drying layer, light frosted plastic handles, perspective glass, temperature regulation buttons, digital display screens and universal moving wheels. The oven body is made of a tempered aluminum sheet and is coated with paint. The heat dissipation air holes are formed in the right side of the oven body and located in the edges of the baking layers. The heat preservation layer can preserve heat of rice, dishes, soup and other food, the unfreezing layer can unfreeze food through infrared heating, the disinfecting and drying layer can perform disinfection and sterilization with infrared rays, the three baking layers are independent of one another and can operate independently, and the temperature can be independently set for the three baking layers. The perspective glass is installed at the front sections of the baking layers, and thus the condition of food in the oven can be observed in due time. The three baking layers are provided with the temperature regulation buttons, the digital display screens and the light frosted plastic handles. The four universal moving wheels are arranged at the bottom of the oven body, and thus the oven can be conveniently transported or moved.