Does the spark plug of the car work when striking a fire or always when driving?

The spark plug is always working. As long as the engine is still working after starting, the spark plug is working.

Spark plug is an important part of the engine ignition system, and its main function is to ignite the engine cylinder. The combustible mixture of the engine can burn, mainly relying on the ignition coil to generate high voltage electricity, which passes through the spark plug.

The central electrode of the spark plug breaks through the air to generate an electric spark, which ignites the combustible mixture in the combustion chamber, so the spark plug is very important for the engine.