The utility model discloses a side-frame concealed clip-type connecting wrap angle of a flat plate solar collector, and relates to a connecting element, in particular to a clip-type concealed connecting device used for the side frame of a flat plate solar collector. The side-frame concealed clip-type connecting wrap angle of the flat plate solar collector comprises a wrap angle, a longitudinal side frame and a transverse side frame and is characterized in that a pair of rectangular raised clips and a shuttle are respectively arranged on the inner sides of the longitudinal folded edge and the transverse folded edge of the wrap angle, and rectangular square holes and a shuttle groove are respectively formed on the longitudinal side frame, the transverse side frame in positions corresponding to the rectangular raised clips and the shuttle of the warp angle. The utility model is convenient and rapid when the side frame is mounted, is accurately and reliably positioned, conceals the seams of the longitudinal and the transverse side frames, is not provided with a rivet, self-tapping screw or other connecting pieces, is artistic and has simple structure.