Car air purifiers are also called car purifiers or car air purifiers; they are mainly divided into four types, namely, filter type, electrostatic dust collection type, ozone, and net ion group. The vehicle air purifier is usually composed of a high voltage generating circuit negative ion generator, a micro fan, an air filter and the like. Its working principle is as follows: the micro-fan (also called ventilator) in the machine circulates the air inside the car. The polluted air passes through the PM2.5 filter and the activated carbon filter in the machine to filter or adsorb various pollutants. After passing through the negative ion generator installed in the air outlet (the high voltage in the negative ion generator generates DC negative high voltage), the air is continuously ionized, and a large amount of negative ions are generated, which are sent out by the micro fan to form a negative ion airflow, so as to clean and purify the air.