The invention relates to a novel angle bond for fixing a side frame, and belongs to the technical field of photovoltaic equipment. The angle bond comprises a first inserting plate and a second inserting plate; one end of the first inserting plate is hinged to one end of the second inserting plate; a torsional spring is arranged at the part in which the first inserting plate is hinged with the second inserting plate; through holes are formed in one of the ends of the first inserting plate and the second inserting plate; a central axis of each through hole is parallel with a hinging shaft; both the first inserting plate and the second inserting plate are of an inner hollow structure; a plurality of reinforcing ribs are arranged in the inner hollow structures, wherein the plurality of reinforcing ribs are crisscross arranged in the hollow structures to form a grid structure; a pair of semi-grid connecting rods for fixing are spanned on adjacent two sides of the side frame, wherein the semi-rigid connecting rods are pined to the side frame. According to the angle bond, the semi-rigid connecting rod and the torsional spring are matched to relatively fix the side frame and the angle bond, and therefore, a protecting structure of a photovoltaic battery plate of which the side frame is used as a fixing body is firm, and the side frame can be clamped for a long time through the angle bond.