Abstract: The present invention provides a buffer slide rail with a fixed friction silencing mechanism, comprising an upper rail, a middle rail and a lower rail which are in sliding connection in sequence, wherein a fixed friction silencing assembly for reducing an axial moving speed is arranged between the connection of the upper rail and the middle rail, the fixed friction silencing assembly including an abrasion-resistant convex block which comes into soft contact with or is separated from the connecting convex block as the upper rail moves. The structure is simple, to increase fixed friction between the upper rail and the middle rail, reduce an axial moving speed, achieve a silencing effect, as well as ensure that the upper rail and the middle rail are opened or closed on the lower rail in sequence, improve the transmission stability of the slide rail, and guarantee the normal use of a drawer.