Disclosed a prepreg sizing roll shaft spraying complete machine. The complete machine comprises a main machine base (b1) and a coating mechanism arranged on the main machine base (b1); the complete machine further comprises a feeding structure for performing feeding and an iron powder supply device for absorbing iron powder; a supporting rod (b2) for the installation of the feeding structure is arranged on the main machine base (b1); and the complete machine also comprises an iron powder recycling box (b3) arranged below the iron powder supply device. The prepreg sizing roll shaft spraying complete machine uses automatic control, a very efficient novel roller shaft manufacturing manner is achieved, the finished product yield is high, and the effect is good.