The invention discloses an automatic clamping and discharging mechanism of a spinning clamp. The mechanism comprises a feeding area, a machining area and a discharging area of a workpiece; the automatic clamping and discharging mechanism of the spinning clamp further comprises a clamping device and a detection device; the clamping device comprises a mechanical arm; the mechanical arm comprises a mechanical arm base, a first rotating device, a first mechanical arm, a second mechanical arm, a first rotating motor and a clamping device; the first rotating device comprises a first rotating shaft and a second rotating motor; the clamping device comprises clamping claws and a pushing device, wherein the number of the clamping claws is greater than one; the pushing device comprises pushers whichare the same as the clamping claws in quantity, sliding guide rails which are the same as the pushers in quantity and are connected in a sliding mode, and a first driving motor; the clamping claws arecircumferentially and uniformly distributed in the horizontal direction, and the movement direction of the sliding guide rails is from the circle center to the outer diameter direction; and the detection device comprises a forward and reverse detection table and an outer diameter run-out detection table.