The utility model discloses a buckling device without nails used in a watch core, comprising a first board and a second board, wherein, the first board and the second board are assembled with the inner component support frame of the watch core as a whole, and are used as the shell of the core. The utility model is characterized in that the first board has on its edge at least three unciform down-buckled arms extending towards the second board; the down-buckled arms hook inwards the second board from one side of the second board and make the two boards fastened. With simple structure and easy operation, the utility model can reduce the material cost in the production of watch cores.