The invention relates to a waste heat recovery energy-saving drying oven and a waste heat recovery method thereof. The waste heat recovery energy-saving drying oven comprises a furnace body, a hot airsupply pipeline, a dehumidifying fan, recycling pipelines, dehumidifying air pipelines, temperature and humidity detectors, an automatic regulating valve, drying oven waste heat recovery and utilization systems and a server. The waste heat recovery energy-saving drying oven is characterized in that the furnace body is provided with an air supplementing inlet and the temperature and humidity detectors, the hot air supply pipeline communicates with the furnace body, the furnace body is internally provided with a plurality of drying cavities communicating mutually, and the upper portion of eachdrying cavity is provided with the corresponding dehumidifying air pipeline or the corresponding recycling pipeline; the dehumidifying fan is provided with a recycling opening and an exhaust outlet, and the recycling pipelines and the dehumidifying air pipelines communicate with the recycling opening and the exhaust outlet of the dehumidifying fan correspondingly; the drying oven waste heat recovery and utilization systems are mounted in the dehumidifying air pipelines and the recycling pipelines; and the adjusting regulating valve is mounted at the exhaust outlet of the dehumidifying fan, theair supplementing inlet communicates with the recycling pipelines, and the server is connected with the temperature and humidity detectors, the automatic regulating valve and a hot air supply system.Compared with the prior art, the waste heat recovery energy-saving drying oven and the waste heat recovery method thereof have the characteristics of concise and reasonable structure, convenient use,high energy utilization rate, low cost and the like.