A coffee bean grinder, comprising: a housing assembly comprising a housing, a bearing component, and an outer grinding member, the bearing component being disposed in the housing, the outer grinding member being assembled in the housing, the outer grinding member being disposed below the bearing component; a shaft component assembled in the housing, the shaft component comprising a shaft member, an inner grinding member, and an elastic member, one end of the shaft member comprising a connecting shaft and a shaft cap, the shaft cap being disposed at the connecting shaft, an outer diameter of a bottom end of the shaft cap being greater than an outer diameter of the connecting shaft, the inner grinding member being disposed at the other end of the shaft member, one end of the shaft member passing through the elastic member and the bearing component in order, the elastic member being disposed between the inner grinding member and the bearing component, two ends of the elastic member supporting the inner grinding member and the bearing component respectively, the inner grinding member and the outer grinding member being correspondingly disposed, a grinding gap existing between the inner grinding member and the outer grinding member, the shaft member driving the inner grinding member to rotate relative to the outer grinding member for performing grinding through the cooperation of the inner grinding member and the outer grinding member; and a securing member comprising a body, a securing hole, and a securing groove, a shape of an opening of the securing hole and a shape of an opening of the securing groove being identical to a shape of a periphery of the bottom end of the shaft cap, the securing groove being disposed at the body, the securing hole penetrating the body in correspondence with a position of the securing groove, an opening angular position of the securing groove on a surface of the body being different from an opening angular position of the securing hole on the surface of the body; wherein, when assembling, the shaft cap passes through the securing hole of the securing member correspondingly, where the securing member presses against the bearing component and the elastic member downwardly; when assembled, the elastic member supports the bearing component and the securing member upwardly, the bottom end of the shaft cap is embedded in the securing groove of the securing member, and the securing member is secured between the shaft cap and the bearing component. a housing assembly comprising a housing, a bearing component, and an outer grinding member, the bearing component being disposed in the housing, the outer grinding member being assembled in the housing, the outer grinding member being disposed below the bearing component; a shaft component assembled in the housing, the shaft component comprising a shaft member, an inner grinding member, and an elastic member, one end of the shaft member comprising a connecting shaft and a shaft cap, the shaft cap being disposed at the connecting shaft, an outer diameter of a bottom end of the shaft cap being greater than an outer diameter of the connecting shaft, the inner grinding member being disposed at the other end of the shaft member, one end of the shaft member passing through the elastic member and the bearing component in order, the elastic member being disposed between the inner grinding member and the bearing component, two ends of the elastic member supporting the inner grinding member and the bearing component respectively, the inner grinding member and the outer grinding member being correspondingly disposed, a grinding gap existing between the inner grinding member and the outer grinding member, the shaft member driving the inner grinding member to rotate relative to the outer grinding member for performing grinding through the cooperation of the inner grinding member and the outer grinding member; and a securing member comprising a body, a securing hole, and a securing groove, a shape of an opening of the securing hole and a shape of an opening of the securing groove being identical to a shape of a periphery of the bottom end of the shaft cap, the securing groove being disposed at the body, the securing hole penetrating the body in correspondence with a position of the securing groove, an opening angular position of the securing groove on a surface of the body being different from an opening angular position of the securing hole on the surface of the body; wherein, when assembling, the shaft cap passes through the securing hole of the securing member correspondingly, where the securing member presses against the bearing component and the elastic member downwardly; when assembled, the elastic member supports the bearing component and the securing member upwardly, the bottom end of the shaft cap is embedded in the securing groove of the securing member, and the securing member is secured between the shaft cap and the bearing component.