Damping air cylinder without adjustment for use in a prosthetic joint, comprising: an air cylinder body (1), in which an air chamber (11) is formed inside the air cylinder body (one)； a piston (2), in which one end of the piston (2) is slidably disposed in the air chamber (11) and the other end extends to the outside of the air cylinder body (1)； the piston (2) divides the air chamber (11) into an upper air chamber (111) and a lower air chamber (112), and performs an alternative movement between a first position and a second position in the air chamber (eleven)； a first check valve (3), in which the first check valve (3) is arranged in the piston (2), an upper airway (12), in which the upper airway (12) is formed inside the air cylinder body (1) and connects the upper air chamber (111) with the outside； a second check valve (4), in which the second check valve (4) is arranged in the upper airway (12), one end of the second check valve (4) is connected to the outside and the another end is connected to the upper air chamber (111) to allow air to flow unidirectionally from the outside to the upper air chamber (111)； and a lower airway (13), in which the lower airway (13) is formed inside the air cylinder body (1) and connects the lower air chamber (112) with the outside； characterized in that one end of the first check valve (3) is connected to the upper air chamber (111) and the other end is connected to the lower air chamber (112) in order to allow air to flow unidirectionally from the upper air chamber (111) to the lower air chamber (112)； wherein an inside bore diameter of the upper airway (12) is greater than that of the lower airway (13) so that the inlet flow rate of the air chamber (11) is greater than the flow rate outputCilindro de aire de amortiguación sin ajuste para su uso en una articulación de prótesis, que comprende: un cuerpo de cilindro de aire (1), en el que una cámara de aire (11) está formada en el interior del cuerpo de cilindro de aire (1)； un p
