The invention discloses a two-phase swinging plate cam movable teeth frame output type internal combustion engine, relates to the field of fuel gas power, and belongs to the field of multi-cylinder internal combustion engines. According to the novel internal combustion engine provided by the invention, pistons act on a slot type two-phase swinging plate cam wave shock device through push rods and universal ball assemblies. Power is transmitted to an output shaft in key jointwith a movable teeth frame through the slot type two-phase swinging plate cam wave shock device via a two-phase swinging plate axial thrust transmission mechanism. Steel ball oscillating teeth are in multi-teeth engagement with an end gear, the movable teeth frame and the slot type two-phase swinging plate cam wave shock device. The slot type two-phase swinging plate wave shock device enables the internal combustion engine to be integrated with a reducer, so that the internal combustion engine does not need to be additionally equipped with a reducer. The rotating speed of the output shaft depends on the transmission ratio of the two-phase swinging plate axial thrust transmission mechanism, and low-speed large torque can be output. The internal combustion engine is free of eccentric mass, air cylinders are arranged in the axial direction, the structure is simple and compact, the axial size and radial size are small, operation is stable, the overlap ratio is large, the bearing capacity is high, and the two-phase swinging plate cam movable teeth frame output type internal combustion engine can be widely applied to the fields of engineering machinery, military and the like needing high power, such as excavators and armored cars.