It is mainly composed of batteries, Ignition switches, Ignition coils and spark plugs. The battery supplies the electrical energy needed for the ignition system. The ignition switch is connected or disconnected to the ignition system. The ignition coil stores ignition energy and converts the battery voltage to ignition high pressure. The distributor consists of a disconnection and an ignition advance mechanism. The function of the breaker is to connect or cut off the primary circuit of the ignition coil; The function of the distributor is to transmit the ignition high pressure generated by the ignition coil to each cylinder spark plug according to the order of work of the engine; The ignition advance mechanism is used to adjust the ignition advance angle with the change of engine speed, load and gasoline octane value. The spark plug introduces the ignition high pressure into the cylinder combustion chamber and generates electric sparks between the electrodes to ignite the mixture gas.