The invention discloses a steam cycling and energy-saving device including a device body, a circulation mechanism and a heat insulation mechanism. The main body of that device includes an outlet pipe,a drainage pipe, a drain gate valve, a steam cabinet, partitions and steam chambers, the circulation mechanism includes a steam outlet conduit, a steam outlet pipe I, a one-way check valve, a steam outlet pipe II, an exhaust fan, a steam line one, a one-way check valve II, a steam transmission pipe II, a steam generator, a steam inlet pipe and a steam outlet pipe, the heat insulation mechanism isinstalled on the left end surface of the steam cabinet. The heat insulation mechanism comprises a water storage cover, a water adding hole, a plug, a sealing gasket, a hollow pipe and a flange. Compared with the prior art, the heat insulation mechanism has the following beneficial effects: waste of energy is reduced, efficiency of a steam cabinet is improved, use safety of the steam cabinet is increased, service life of the steam cabinet is prolonged, and the purpose of heat insulation and scald prevention is achieved.