Pneumatic ejector pin clamp

The invention relates to a pneumatic ejector pin clamp, which comprises four fixing blocks, wherein the fixing blocks are positioned at the top corner, pneumatic ejector pins are arranged between the upper fixing blocks and the lower fixing blocks, and respectively comprise air paths and an expansion ring, the air paths are positioned at the two sides, and are communicated with an air cylinder, the other side of each air cylinder is provided with a clamping head, each clamping head is connected with the interior of the corresponding air cylinder through a sealed air ring, each expansion ring is arranged at the periphery of the corresponding pneumatic ejector pin, the cross section of each expansion ring is in a trapezoid shape, and one part of the upper bottom surface of each trapezoidal cross section extends into the corresponding air cylinder. The pneumatic ejector pin clamp has the advantages that each ejector pin is pushed by the hydraulic force, so the corresponding ejector pin is guaranteed to effectively clamp a workpiece; the hydraulic air cylinder is fixed by a balance and stable structure, so the swinging of each air cylinder is effectively avoided, and the practicality is realized.