The invention discloses an autothermal reforming device for producing hydrogen from natural gas, comprising an autothermal reforming reactor, a combustion chamber outer wall, a combustor, an internal heat exchanger coiler, an external heat exchanger coiler, a combustion tail gas outlet, a flange and a mixing valve. The combustion chamber outer wall is a hollow round pipe which is internally provided with the autothermal reforming reactor, the external heat exchanger coiler comprises a natural gas heat exchange pipe and a water heat exchange pipe which are spirally wound outside the combustion chamber outer wall from bottom to top respectively, the internal heat exchanger coiler is spirally wound on a reaction pipe from top to bottom, a feed gas inlet pipe is arranged at the bottom of one side of the reaction pipe, one end of the feed gas inlet pipe is connected into the reaction pipe, and the other end of the feed gas inlet pipe is connected with the internal heat exchanger coiler through a high-temperature-resistant joint. The invention for autothermal reforming hydrogen production has high start speed, low system energy consumption, small device size and less floor area, can ensure the reaction operation, without additional energy, is convenient and practical to mount and dismount, and can be arranged in idle spaces on a balcony, under an eave, and the like.