The invention discloses an interconnection method of a flexible board and a rigid board and a system, relating the electronic technical filed; the flexible board and the rigid board are interconnected by automation SMT assembling technology without arranging a connector additionally, so as to reduce the interconnecting technical difficulty; the interconnection method has low cost, high efficiency, strong processability and high product yield. The interconnection method of the flexible board and the rigid board is that: at least one soldering pad is arranged on the rigid board, a soldering padcorresponding to the soldering pad on the rigid board is arranged on the flexible board, and then the rigid board and the flexible board which are stacked up with corresponding soldering pads are located by a tooling fixture; by utilizing the soldering pads of the rigid board and the flexible board and adopting SMT, the interconnection of the rigid board and the flexible board is realized; the method is suitable for occasions that the rigid board and the flexible board are interconnected.