The utility model relates to an assembling structure of a tripping device, which comprises connecting shafts and a tripping device shell, wherein the side wall of the tripping device shell is provided with at least two connecting shafts, one end of each connecting shaft is provided with a fixing portion which is stepped in shape, each fixing portion is formed by at least two fixing steps which are different in diameter, and the fixing portions can be connected and assembled with rivet holes in the side wall of the tripping device shell respectively; the other end of each connecting shaft is provided with an assembling portion which can be connected and assembled with a switching mechanism rivet hole of a switching mechanism, the assembling portion is stepped in shape and formed by at least two assembling steps which are different in diameter, and the fixing portion and the assembling portion are provided with a baffle plate therebetween which is installed at the outer wall of the connecting shaft in a surrounding mode. The assembling structure of the tripping device provided by the utility model is high in assembling efficiency, simple in structure and stable in installation.