To provide a rotary high-pressure gas-powered engine that provides a highly thermally efficient power source using the enormous
volume change caused by the
vaporization of
liquid water as a power source. [Solution] The present invention relates to a rotary high-pressure gas-powered engine, which includes a rotor including a plurality of cylinders and a plurality of vent holes communicating with the interiors of the cylinders, a spindle 30 inserted through the
stator mechanism and the rotor, a plurality of pistons 40 movably housed in the cylinders, each having a
piston shaft rod protruding axially from the plurality of slots and moving along the rail, and a plurality of air covers 50, in which high-pressure gas passes through the cylinders 21 to push the pistons, and after a
power stroke, the pistons move to
discharge the high-pressure gas in the cylinders.