The invention relates to an intelligent grinding device for an adjustable rail surface. The intelligent grinding device comprises a grinding support plate, and the right and left sides of the lower end of the grinding support plate are symmetrically provided with two moving mechanisms of which the inner sides are provided with two grinding branched chains separately; the two grinding branched chains are connected by welding, and the position between the two grinding branched chains is used for arranging a rail required for grinding; the upper ends of the two grinding branched chains are weldedwith two movable sliding columns separately, and the upper ends of the two movable sliding columns are provided with two movable sliding chutes in a sliding fit manner; the upper ends of the two movable sliding chutes are welded with the lower end faces of the grinding support plates separately; under the auxiliary limit of the two movable sliding columns and the two movable sliding chutes, the two grinding branched chains are driven by the two moving mechanisms to move back and forth for stable grinding; each moving mechanism comprises two grinding lugs welded with the lower end of the grinding support plate symmetrically. According to the intelligent grinding device provided by the invention, the full-automatic grinding function of the rail can be achieved, and manual operation is not required; and the degree of automation is high.