Clamping mechanism for positioning after clamping

The utility model discloses a clamping mechanism for positioning after clamping. The clamping mechanism comprises a lifting positioning part and a clamping part. The lifting positioning part is provided with a first lifting power source and a manual clamping assembly in driving connection with the first lifting power source, and the first lifting power source drives the manual clamping assembly to ascend and descend; the clamping part is arranged on the adjacent side of the lifting positioning part, the clamping part is provided with a second lifting power source, an expansion block in driving connection with the second lifting power source and a plurality of expansion pins which are connected to the side circumferential face of the expansion block in a sliding mode and distributed at equal angles, and the expansion block is driven by the second lifting power source to do lifting motion; the expansion blocks ascend and descend so that the expansion pins can be driven to stretch out and retract back. The clamp