The individual ignition method is that each cylinder is assigned an ignition coil, and the ignition coil is directly mounted on the top of the spark plug, which also eliminates the high voltage line. This kind of ignition method achieves accurate ignition through the camshaft sensor or by monitoring cylinder compression. It is suitable for any number of cylinders of the engine and is especially suitable for the engine with 4 valves per cylinder. Because the spark plug ignition coil assembly can be installed in the middle of a dual overhead camshaft (DOHC), full use is made of clearance space. Due to the cancellation of distributors and high-voltage lines, energy conduction losses and leakage losses are minimal, there is no mechanical wear, and the ignition coils and spark plugs of the cylinders are assembled together with external metal packages, which greatly reduces electromagnetic interference and can ensure the normality of the engine electronic control system. jobs.