Abstract: A structure of a reversing actuating module of reciprocating pneumatic tools adopts an adaptation between the stage-shaped reversing block and the stage-shaped receiving groove. The bottom end of the air inlet flow path configured in the center of the air pressure inlet seat is not connected to the stage-shaped receiving groove through a straight hole, but a twisted hole formed through the inclined hole configured in the air pressure inlet seat to connect the air inlet flow path alternatively. Further, the diameter of the lower end of the inclined hole is partially enlarged so that the auxiliary ventilating part is corresponded to the area of expanding groove of the stage-shaped receiving groove. The structure can omit the configuration of a spacing ring component, while maintaining the function of reversing actuation. Therefore, the present invention can help to reduce production and processing cost, assembly time, and defect rate.