Disclosed are two system devices for stratified injecting the recirculated exhaust gas and high-specific-heat-capacity or inert gas for clean combustion of an internal combustion engine. The former is composed of an exhaust gas recirculation system, an injection system, and a power system. The latter is composed of four parts, and a high-specific-heat-capacity gas or inert gas channel is added. Injectors can be arranged at any position in the cylinder between a top dead center and a bottom dead center of a piston in a cylinder; 1-3 layers of injectors can be arranged; and 2-6 injectors can be arranged on each layer. Gas participating in combustion enters the cylinder from two intake channels, namely, a scavenging port of the internal combustion engine and the injectors; an in-cylinder swirl ratio can be remarkably increased through kinetic energy carried by the gas; and fuel-gas mixing is promoted, and the combustion rate is increased.