A junction box comprising: a protecting case; an anchoring device; a plug-in terminal connector; an optical unit connection box; an optical fiber connector; and an electrical connector; wherein each of the plug-in terminal connector and the optical unit connection box is received in the protecting case, each of the anchoring device, the optical fiber connector and the electrical connector is mounted on the protecting case; wherein the anchoring device comprises a fixing member and two wire passing members connected to the fixing member, the fixing member defines a line channel, each of the two wire passing members defines a wire passing holes; wherein the fixing member comprises a positioning portion, a protrusion protruding from one end of the positioning portion, and a connecting portion connected to the other end of the positioning portion, the line channel penetrates the positioning portion, the protrusion and the connecting portion; wherein the line channel comprises a first channel extending through the positioning portion and the protrusion, and two second channels extending through the connecting portion; wherein the two second channels communicate with the first channel to form an inverted Y-shaped channel, a diameter of the first channel (217: being larger than a diameter of the second channel, the line channel allowing passage for the cables, wherein the two wire passing members are fixed on the connecting portion of the fixing member and correspond to the two second channels, such that each wire passing hole communicates with the corresponding second channel, wherein two bundles of cables can pass through the wire passing hole and enter the two second channels to meet in the first channel and enter the protecting case such that the cables are fixed and sealed by the anchoring device. a protecting case; an anchoring device; a plug-in terminal connector; an optical unit connection box; an optical fiber connector; and an electrical connector; wherein each of the plug-in terminal connector and the optical unit connection box is received in the protecting case, each of the anchoring device, the optical fiber connector and the electrical connector is mounted on the protecting case; wherein the anchoring device comprises a fixing member and two wire passing members connected to the fixing member, the fixing member defines a line channel, each of the two wire passing members defines a wire passing holes; wherein the fixing member comprises a positioning portion, a protrusion protruding from one end of the positioning portion, and a connecting portion connected to the other end of the positioning portion, the line channel penetrates the positioning portion, the protrusion and the connecting portion; wherein the line channel comprises a first channel extending through the positioning portion and the protrusion, and two second channels extending through the connecting portion; wherein the two second channels communicate with the first channel to form an inverted Y-shaped channel, a diameter of the first channel (217: being larger than a diameter of the second channel, the line channel allowing passage for the cables, wherein the two wire passing members are fixed on the connecting portion of the fixing member and correspond to the two second channels, such that each wire passing hole communicates with the corresponding second channel, wherein two bundles of cables can pass through the wire passing hole and enter the two second channels to meet in the first channel and enter the protecting case such that the cables are fixed and sealed by the anchoring device.