The utility model relates to a communication cable testing device which comprises a power supply, a light-emitting diode, a first communication cable insertion end, and a second communication cable insertion end, wherein the first communication cable insertion end and the second communication cable insertion end are used for respectively connecting two ends of a to-be-detected communication cable. One end of the power supply is connected to the second communication cable insertion end through the light-emitting diode, and the other end of the power supply is connected to the first communication cable insertion end. The utility model provides the communication cable testing device which is convenient for detection, and the detection result is reliable.