A button assembly, comprising a side frame, a signal triggering element fixedly disposed inside the side frame, and a button configured to extend through the side frame, wherein the side frame defines a button hole; two limiting protrusion are arranged on an inner wall of the button hole; the button comprises: a button post, received in the button hole to further extend through the side frame and disposed adjacent to the signal triggering element; a button cap, movably connected to the button post and at least partially received in the button hole; and a snap board, fastened to a side of the button cap facing the signal triggering element, wherein the snap board is configured with two hooks engaged with the two limiting protrusions respectively for limiting movement of the button, wherein the button assembly is characterized in that, the two limiting protrusions are disposed on two opposite inner walls of the button hole along a length direction of the button hole; two ends of the snap board corresponding to two ends of the button cap along a length direction of the button cap are configured with the two hooks respectively; the button cap defines two rivet holes at the two ends of the button cap along the length direction of the button cap; each of the two rivet holes is defined by a side of the button cap facing the button post being recessed inwardly; the button further comprises two rivets, extending through the snap board and received into the two rivet holes respectively, outer walls of the two rivets are engaged with inner walls of the two rivet holes with an interference fit; the button cap defines a fastening groove, the fastening groove is defined by the side of the button cap facing the button post being recessed inwardly; a portion of an outer face of the snap board facing the button cap is protruded to be a protrusion, the protrusion is fixedly received in the fastening groove; an inner face of the snap board facing the button post is recessed inwardly at a position corresponding to the protrusion to define a recess corresponding to the protrusion; an end of the button post is connected to the snap board and the button cap through the recess; and the button further comprises an elastic gasket fixedly connected to an end of the button post away from the signal triggering element and an inner face of the snap board facing the button post and at least a portion of the elastic gasket is fixedly received in the recess. the side frame defines a button hole; two limiting protrusion are arranged on an inner wall of the button hole; the button comprises: a button post, received in the button hole to further extend through the side frame and disposed adjacent to the signal triggering element; a button cap, movably connected to the button post and at least partially received in the button hole; and a snap board, fastened to a side of the button cap facing the signal triggering element, wherein the snap board is configured with two hooks engaged with the two limiting protrusions respectively for limiting movement of the button, a button post, received in the button hole to further extend through the side frame and disposed adjacent to the signal triggering element; a button cap, movably connected to the button post and at least partially received in the button hole; and a snap board, fastened to a side of the button cap facing the signal triggering element, wherein the snap board is configured with two hooks engaged with the two limiting protrusions respectively for limiting movement of the button, wherein the button assembly is characterized in that, the two limiting protrusions are disposed on two opposite inner walls of the button hole along a length direction of the button hole; two ends of the snap board corresponding to two ends of the button cap along a length direction of the button cap are configured with the two hooks respectively; the button cap defines two rivet holes at the two ends of the button cap along the length direction of the button cap; each of the two rivet holes is defined by a side of the button cap facing the button post being recessed inwardly; the button further comprises two rivets, extending through the snap board and received into the two rivet holes respectively, outer walls of the two rivets are engaged with inner walls of the two rivet holes with an interference fit; the button cap defines a fastening groove, the fastening groove is defined by the side of the button cap facing the button post being recessed inwardly; a portion of an outer face of the snap board facing the button cap is protruded to be a protrusion, the protrusion is fixedly received in the fastening groove; an inner face of the snap board facing the button post is recessed inwardly at a position corresponding to the protrusion to define a recess corresponding to the protrusion; an end of the button post is connected to the snap board and the button cap through the recess; and the button further comprises an elastic gasket fixedly connected to an end of the button post away from the signal triggering element and an inner face of the snap board facing the button post and at least a portion of the elastic gasket is fixedly received in the recess.