The invention belongs to the technical field of heat engines, and particularly relates to an efficient
internal combustion engine with a multi-stage auxiliary air
cylinder set. Comprising a main cylinder group, an auxiliary cylinder group and a gas common channel, the main cylinder group comprises a plurality of main cylinders with one or two air inlets, fuel is combusted in the main cylinders, and
waste gas exhausted by the main cylinder group is utilized by the auxiliary cylinder group; the auxiliary air cylinder sets are arranged in a multi-stage mode, each stage of auxiliary air
cylinder set comprises n auxiliary cylinders, and n is larger than or equal to 1. The auxiliary cylinder is an
internal combustion engine type auxiliary cylinder of a two-way pushing
piston type structure. And the gas public channel is communicated with the air inlet valves of the auxiliary cylinders at the same stage and supplies gas to the auxiliary cylinders. The multi-stage auxiliary
cylinder set is used for doing work for multiple times, gas energy is almost completely utilized, the problem that
waste gas takes away a large amount of energy is thoroughly solved, the efficiency and power of the
internal combustion engine are greatly improved, the energy-saving and emission-reducing effects are good, the structure is compact, the
power density is high, the application range is wide, and the auxiliary cylinders do not need an
oil supply system or an
ignition system. The structure is simple and easy to manufacture.