The invention discloses a sliding rail support, which is formed by a front support and a rear support, wherein the front support comprises a first main plate; edges of the upper side and the lower side of the first main plate are bent to the inner sides to form side plates; the side plates and the first main plate form two triangular sliding grooves; the two side plates are in a toe-in type; the rear support comprises a second main plate; edges of the upper side and the lower side of the second main plate are bent to the inner sides to form sliding sheets; the sliding sheets are in a toe-out type; the rear support is movably sleeved inside the sliding grooves of the front support via the sliding sheets; and the sliding rail is fixed at the outer side of the front support. Through improvement on the sliding rail support of the prior art, the arc-shaped sliding grooves of the original front support are changed into the triangular sliding grooves, the two triangular sliding grooves form a toe-in structure, and when the sliding rail support bears a force, the toe-in structure of the front support and the toe-out structure of the rear support are closely matched, strength of the connection part between the front support and the rear support is greatly enhanced, the sliding rail support is not easy to deform and get loose, and the use cost is reduced.