The invention discloses an automatic sanding fixture for an industrial robot. A positioning disc (1) is matched with a flange at the tail end of the industrial robot through a boss (3), a pin hole (2) and a screw hole (4); a fixed shaft (5) is connected with a supporting side plate; a sleeve (6) is loosely sleeved on the fixed shaft (5) and is connected with the fixed shaft (5) through a locking screw (7); an upper bracket (10) is connected to the lower end of the sleeve (6); a connecting plate (11) is used for connecting the upper bracket (10) with a lower bracket (12) together; a cylinder (13) is connected with the lower bracket (12); a cylinder guide rod sleeve (14) is connected to the lower end of the lower bracket (12); a cylinder guide rod (15) is arranged in the cylinder guide rod sleeve (14); a finger clamp sleeve (16) is connected with the cylinder guide rod sleeve (14); and a finger clamp (17) is arranged in a groove of the finger clamp sleeve (16). In the fixture, a cylinder is used as a power source; the finger clamp is opened through an inner hole conical surface or an outer circular conical surface of the cylinder guide rod so as to clamp a part; and the part is rotated at the angle of 90 DEG through a position changing mechanism so as to ensure machining quality.