An adjustment-free cushioning air cylinder includes an air cylinder body (1), a piston (2), a first check valve (3), an upper air way (21), a second check valve (4) and a lower air way (13). An air chamber (11) is formed inside the air cylinder body. The piston slides in the air chamber. One end of the piston extends to the external of the air cylinder body. The piston does a reciprocating movement in the air chamber and divides the air chamber into an upper air chamber (111) and a lower air chamber (112). The first check valve is disposed in the piston, one end of the first check valve is connected to the upper air chamber, and the other end is connected to the lower air chamber. The upper air way connects the upper air chamber with the outside. The adjustment-free cushioning air cylinder of the invention does not need to adjust the entering flow rate of the air, but the entering flow rate can be automatically adjusted to produce cushioning resistance as the user is walking according to the walking speed. The present invention has a simple structure, high cushioning performance, lower cost, and is not easy to damage, thus can greatly improve the product competitiveness.
