The invention discloses a membrane-separation hydrogen extraction device, belonging to the technical field of chemical equipment design. The membrane-separation hydrogen extraction device comprises a left membrane separator, outlet valves, emptying valves, a right membrane separator and a tail gas regulating valve, wherein the top ends of the left membrane separator and right membrane separator are connected with a triple-inlet main pipe of a compressor, and permeated gas outlets of the joints are respectively provided with an outlet valve and an emptying valve; the bottoms of the left membrane separator and right membrane separator are connected with a tail gas outlet; the right side of the tail gas outlet is connected with the tail gas regulating valve; and an outlet valve and an emptying valve are arranged between the tail gas regulating valve and the bottom of the right membrane separator. According to the membrane-separation hydrogen extraction device disclosed by the invention, the left membrane separator and right membrane separator can be completely isolated without mutual interference; and thus, when the membrane separators are started or stopped, no inverse pressure difference can be formed, the corrective maintenance of one membrane separator does not influence the normal operation of the hydrogen recovery and unpowered ammonia recovery units, and the treated gas distribution and the recovery efficiency regulation of the separators are convenient.