The invention discloses a board splicing machine. The board splicing machine comprises a machine frame and a board conveying device installed on the machine frame, wherein the board conveying device comprises a bottom board conveying belt for conveying bottom boards forwards, and a side board conveying groove formed in one side of the bottom board conveying belt, and one side, close to the bottom board conveying belt, of the front end of the side board conveying groove is provided with a side board outlet; a gluing device is arranged beside the inlet end of the bottom board conveying belt; an aligning device corresponding to the side board outlet is arranged in front of the side board outlet, and an induction device corresponding to the aligning device and inducting the positions of the bottom boards is further installed on the portion, beside the bottom board conveying belt, of the machine frame; a nail gun is arranged between the side board outlet and the aligning device; the board conveying device, the aligning device and the nail gun are further connected with a control device, and the input end of the control device is connected with the induction device; a pressing and connecting device for pressing and airing the bottom boards and side boards is arranged in front of the outlet end of the bottom board conveying belt. The board splicing machine is reasonable in structure and convenient to use, the machining efficiency can be substantially improved, consumption of wood can be reduced, and cost can be saved.