Non-surface-electrified PTC heater is a kind of large power non-surface-electrified PTC heater with wind blowing. PTC element is fixed in aluminum tube and keeps insulated with the aluminium tube. Alar or groove shape heat diffusing slice is fixed on the aluminium tube. The large-power heater has a series of advantages such as safety, reliablity, stable power, quite, long life, excellent machinery intension and so on. Because of its good safety performance, non-surface-eletrified PTC heater is now mainly used in large-power house heater such as cold/warm air-conditioners, fan heaters, disinfecting cabinets, dryers and so on.