The invention relates to a connecting clamping buckle used for a photovoltaic assembly frame. The connecting clamping buckle is composed of a left clamping fit piece and a right clamping fit piece; afirst photovoltaic panel storing groove and a second photovoltaic panel storing groove are formed in each of the left clamping fit piece and the right clamping fit piece in a back against mode, a diversion groove is further formed in the left clamping fit piece, the bottom wall of the left clamping fit piece is arranged obliquely upwards, and the top wall of the left clamping fit piece is proppedon the top wall of the right clamping fit piece; and a tilted-upward flying edge is arranged on the right clamping fit piece, inserted into the diversion groove and divides the diversion groove into afirst diversion groove and a second diversion groove, gaps are arranged between the flying edge and the top wall of the diversion groove as well as between the flying edge and the side wall of the diversion groove, and vertical-downward impermeable water edge is arranged at the bottom of the flying edge. As a result, under the normal conditions, the drainage requirements can be met only through the first diversion groove, when the drainage amount is high, the second diversion groove also plays the role, more importantly, the impermeable water edge arranged on the flying edge can make the water flow overflowed from the first diversion groove completely flow into the second diversion groove to prevent the water flow from leaking into the building.