1. Quasi-type spark plug: The insulator skirt is slightly retracted into the end face of the casing, and the side electrode is outside the end face of the casing, which is the most widely used one.

2. Spherical protrusion spark plug: The insulator skirt is long and protrudes beyond the end face of the housing. The utility model has the advantages of large heat absorption and good anti-pollution ability, and can be directly cooled by the intake air to lower the temperature, and thus is not easy to cause hot ignition, so the heat adaptation range is wide.

3. Electrode type spark plug: The electrode is very thin, characterized by strong spark and good ignition ability. It can ensure the engine to start quickly and reliably in the cold season, and the heat range is wide, which can meet various purposes.

4. Seat type spark plug: The housing and the screw-in thread are tapered, so that the gasket can be used to maintain a good seal, thereby reducing the volume of the spark plug, which is more advantageous for the design of the engine.

5, the pole type spark plug: The side electrode is generally two or more, the advantage is that the ignition is reliable, the gap does not need to be adjusted frequently, so it is often used on some gasoline engines where the electrode is easy to ablate and the spark plug gap cannot be adjusted frequently.

6. Face-flash type spark plug: It is a creeping gap type, which is the coldest type of spark plug, and the gap between the center electrode and the end face of the casing is concentric.

In addition, in order to suppress the interference of the ignition system of the car, a resistive type and a shield type spark plug are produced. The resistive spark plug is equipped with a 5-10kΩ resistor in the spark plug. The shielded spark plug uses a metal housing to seal the entire spark plug shield. Shielded spark plugs not only prevent radio interference, but also waterproof and explosion-proof applications.