Abstract: Processing device for flange includes processing table. Feeding and discharging conveying rollers are separately arranged on two sides of processing table, which includes bottom frame. Fixing table is fixedly arranged on middle part of bottom frame. Front side of bottom frame is provided with sliding base, and back side is provided with driving frame. Driving frame is rotationally provided with vertical driving roller. Rotation frame is rotationally arranged on upper end of driving frame and slidably provided with upper-side moving frame. Upper-side moving frame is provided with liftable lifting table, lower end of which is rotationally provided with upper-side driven roller. Inner-supporting clamping mechanism is arranged inside upper-side driven roller; and lower end thereof is provided with lower-side driven roller that can slide horizontally. Butting mechanism is arranged between upper-side and lower-side driven rollers, and clutch mechanism is arranged between rotation frame and driving roller.