Powder supply mechanism

The invention discloses a powder supply mechanism which comprises a material cavity, a mixer and a powder separator, wherein the mixer is connected with mixed powder and compressed gas through a pipeline on the material cavity; the separator is used for separating powder and compressed gas. According to the invention, the mixer for regulating the proportion of powder to compressed gas is additionally arranged to avoid the possibility of powder blockage; in case of no powder, one-key powder feeding can be realized through a signal switch without opening the material cavity, so that the operation is convenient; in addition, the powder separator for separating powder and compressed gas is adopted to effectively separate powder so as to avoid air pollution; moreover, filtered gas is reused for recycling waste powder, so that the cost is reduced. At the same time, an automatic control circuit is adopted for automatically detecting powder amount and the internal temperature and giving corresponding response, so that the service life of a photosensitive drum is greatly prolonged.