An optical fiber connection device, comprising: a base plate; at least one adapter for receiving optical fiber connectors (8, 9); a rotating and fixing mechanism being provided on the base plate and being connected with the adapters, the rotating and fixing mechanism comprising: a fixing portion for fixedly connecting with the adapter; and a rotating portion being rotatably connected to the base plate, through which the mechanism can shift between an operation position and a receiving/releasing position; and a positioning member for stably holding the rotating and fixing mechanism in the operation position or the receiving/releasing position, and limiting the rotation angle of the mechanism and that of the adapter within a predetermined angle range, characterized in that the positioning member comprises: a protrusion being formed on one sidewall of the case; an arc groove being formed on the other sidewall opposite to the one sidewall of the case; and two supporters (11A, 11B) being located at both outermost sides of the base plate, one of the two supporters (11A, 11 B) having a protrusion thereon, the other of the two supporters (11A, 11 B) having an arc groove therein, wherein the protrusion of the case or the supporter is fitted with the adjacent arc groove of the adjacent case or the adjacent supporter, wherein when the protrusion reaches a lower end of the arc groove, the rotating and fixing mechanism is held in the operation position; when the protrusion reaches an upper end of the arc groove, the rotating and fixing mechanism is held in the receiving/releasing position.. a base plate; at least one adapter for receiving optical fiber connectors (8, 9); a rotating and fixing mechanism being provided on the base plate and being connected with the adapters, the rotating and fixing mechanism comprising: a fixing portion for fixedly connecting with the adapter; and a rotating portion being rotatably connected to the base plate, through which the mechanism can shift between an operation position and a receiving/releasing position; and a positioning member for stably holding the rotating and fixing mechanism in the operation position or the receiving/releasing position, and limiting the rotation angle of the mechanism and that of the adapter within a predetermined angle range, characterized in that the positioning member comprises: a protrusion being formed on one sidewall of the case; an arc groove being formed on the other sidewall opposite to the one sidewall of the case; and two supporters (11A, 11B) being located at both outermost sides of the base plate, one of the two supporters (11A, 11 B) having a protrusion thereon, the other of the two supporters (11A, 11 B) having an arc groove therein, wherein the protrusion of the case or the supporter is fitted with the adjacent arc groove of the adjacent case or the adjacent supporter, wherein when the protrusion reaches a lower end of the arc groove, the rotating and fixing mechanism is held in the operation position; when the protrusion reaches an upper end of the arc groove, the rotating and fixing mechanism is held in the receiving/releasing position.. a fixing portion for fixedly connecting with the adapter; and a rotating portion being rotatably connected to the base plate, through which the mechanism can shift between an operation position and a receiving/releasing position; and a positioning member for stably holding the rotating and fixing mechanism in the operation position or the receiving/releasing position, and limiting the rotation angle of the mechanism and that of the adapter within a predetermined angle range, characterized in that the positioning member comprises: a protrusion being formed on one sidewall of the case; an arc groove being formed on the other sidewall opposite to the one sidewall of the case; and two supporters (11A, 11B) being located at both outermost sides of the base plate, one of the two supporters (11A, 11 B) having a protrusion thereon, the other of the two supporters (11A, 11 B) having an arc groove therein, wherein the protrusion of the case or the supporter is fitted with the adjacent arc groove of the adjacent case or the adjacent supporter, wherein when the protrusion reaches a lower end of the arc groove, the rotating and fixing mechanism is held in the operation position; when the protrusion reaches an upper end of the arc groove, the rotating and fixing mechanism is held in the receiving/releasing position.. a protrusion being formed on one sidewall of the case; an arc groove being formed on the other sidewall opposite to the one sidewall of the case; and two supporters (11A, 11B) being located at both outermost sides of the base plate, one of the two supporters (11A, 11 B) having a protrusion thereon, the other of the two supporters (11A, 11 B) having an arc groove therein, wherein the protrusion of the case or the supporter is fitted with the adjacent arc groove of the adjacent case or the adjacent supporter, wherein when the protrusion reaches a lower end of the arc groove, the rotating and fixing mechanism is held in the operation position; when the protrusion reaches an upper end of the arc groove, the rotating and fixing mechanism is held in the receiving/releasing position..