NOVELTY - Recovering hydrogen from exhaust gas of chlorate electrolysis comprises removing chlorine and carbon dioxide by electrolytic cell through electrolysis salt water and exhaust gas, recycling exhaust gas through a pipe and then placing into water cooling tower and first and second alkali washing towers, conveying the defoamed gas into first oxygen remover, enabling hydrogen with oxygen, conveying high-temperature gas after oxygen removal into a heat exchanger to cool, conveying a cooled gas into a third water-cooling tower, conveying hydrogen into a heat exchanger tube.    USE - The method is useful for recovering hydrogen from exhaust gas of chlorate electrolysis (claimed).    ADVANTAGE - The method simply recovers the hydrogen from exhaust gas of chlorate electrolysis with strong adaptability and reasonability and high purity and quality.    DETAILED DESCRIPTION - Recovering hydrogen from exhaust gas of chlorate electrolysis comprises removing chlorine and carbon dioxide by electrolytic cell through electrolysis salt water and 30 vol.% of exhaust gas, recycling exhaust gas through a pipe and then placing into a water cooling tower and first and second alkali washing towers and washing with 20% of sodium hydroxide and caustic electrolytic exhaust gas to remove carbon dioxide, generating 20% of caustic soda solution at 80 degrees C with sodium hypochlorite, sodium chlorate and sodium chloride, conveying the defoamed gas into a first oxygen remover, enabling hydrogen with oxygen for reacting to remove oxygen, conveying high-temperature gas at 360-420 degrees C after oxygen removal into a heat exchanger to cool, conveying a cooled gas into a third water-cooling tower, conveying 70 vol.% of hydrogen into a heat exchanger tube to heat exchanger at 360-420 degrees C with an inter-tube gas, increasing the temperature of the gas at greater than 200 degrees C, conveying the gas into a second oxygen remover, reducing the content of oxygen in hydrogen to be less than 0.1%, and finally cooling to temperature of lower than 30 degrees C through a fourth water-cooling tower and conveying hydrogen in a gas cabinet, and compressing and bottling the qualified hydrogen.