Abstract: A pile driver with an air pressure buffer comprises a pile following moving part, a rebound part, and an air pressure buffer. The pile following moving part comprises a pile cap (2) contacting the pile (1) and a piston lever (7), and the rebound part is the other part except the moving part. An air pressure buffer provided between the moving part and the rebound part is composed of a buffer piston (3), a buffer cylinder (4) and a vessel (5). The buffer cylinder (4) and the vessel (5) are intercommunicated with each other. Compressed gas (8) is filled in the vessel (5). The buffer piston (3) can slide in the buffer cylinder (4). The pile driver can save energy and accelerate the frequency of driving pile.