The invention discloses a glass splicing seam structure and a glass splicing method of a large glass canopy and solves the technical problem that the glass splicing of the large glass canopy is poor in connection strength and poor in splicing flatness. The glass splicing seam structure is characterized in that a splicing seam (4) is formed between left rectangular double-tempering laminated glass (1) and right rectangular double-tempering laminated glass (2) which are arranged on a light steel keel (3), gaskets (5) are connected between the top surface of the left rectangular double-tempering laminated glass (1) and the top surface of the right rectangular double-tempering laminated glass (2), a self-drilling screw (6) penetrates each gasket (5) to be connected with the light steel keel (3) in a threaded manner, and the splicing seam (4) is filled with glass cement (7). The glass splicing seam structure is simple and convenient in construction process, low in construction cost, high in practicality and capable of guaranteeing the mounting quality of the large glass canopy.