The negative ion generator is a kind of equipment for generating air negative ions. The negative ion air purifier is a kind of environmental optimization electrical appliance which uses the negative ions generated by itself to purify, dust, deodorize and sterilize the air. Both of them are negative ion release devices. Generally speaking, they are called different. Negative ion generation equipment mainly depends on whether it produces small particles of ecological size. According to Professor Lin Jinming's book Environmental Health and Negative Oxygen Ions, air negative ions can be divided into large and small ions according to their mobility. Only small ions, or small ion clusters, can enter organisms. The small negative oxygen ions, or small negative oxygen ion groups, have good biological activity.