A keyboard key structure comprises a lower casing, an upper casing, a press shaft and a spring; the lower casing comprises a base and two hooks extend upward from the base; the upper casing comprises a top wall, an annular peripheral wall around the periphery of the top wall, and a through opening from the top wall, and is further provided with two see-through slots arranged on both sides of the through opening and the hooks are buckled in the see-through slots so that the lower casing and the upper casing are assembled vertically to form an internal cavity; the press shaft is contained in the cavity, and the top of the press shaft passes through the through opening; and the spring is contained in the cavity and elastically supported between the lower casing and the press shaft.