The invention aims at providing an engine layered rapid 
combustion method capable of achieving multi-time 
natural gas spraying. A 
system comprises an air inlet way, an exhaust way, a low-pressure 
natural gas injection valve and a heart-shaped pre-
combustion chamber with an inclined outlet (
single hole), therefore, a rolling flow, a 
spark plug, an in-cylinder high-pressure direct 
injection air injection valve and a main 
combustion chamber are formed in the air flow, the manner of air inlet way low-
pressure injection and in-cylinder high-pressure direct injection is adopted for supplying naturalgas, for different running conditions of an engine, the different proportions of the gas total quantity needed by each cycle in the air inlet way injection and high-pressure direct injection and theair injection rule of an in-cylinder high-pressure direct 
injection air injection valve are adjusted, the 
mixed gas concentration layering from thick to thin is formed in the cylinder from a pre-
combustion chamber outlet to the exterior, the distribution of the 
mixed gas from thick to thin is formed nearby the 
spark plug, and 
natural gas engine layering rapid combustion is achieved. 
Natural gas engine ignition stability is ensured, the 
engine efficiency is improved, and the emissions are reduced.