A water cooler heat exchange tube torsional mode guided wave sensor comprises a top shell and a tubular shell fixedly connected to the bottom of the top shell, wherein a T-shaped structure is formed by the top shell and the tubular shell, and three aerial sockets used for being connected with an external power supply, receiving external excitation signals and outputting signals to the outside are arranged in the top shell. The water cooler heat exchange tube torsional mode guided wave sensor is also provided with a carbon brush used for forming a conducting circuit with a heat exchanger tube to be tested after a power supply is switched on, and a magnet used for making the carbon brush make close contact with a heat exchanger tube plate. A magnetic field generating device connected with connecting leads of the three aerial sockets, used for being inserted into the heat exchanger tube to be tested to generate an axial alternating magnetic field acting on the heat exchanger tube to be tested, and also used for forming a conducting circuit together with the carbon brush and the heat exchanger tube to be tested so as to make the heat exchanger tube to be tested generate a circumferential magnetic field is arranged in the tubular shell. According to the sensor, efficient testing of the heat exchange tube can be achieved without movement, the signal-to-noise ratio of a detection signal is increased, installation is convenient, and the sensor is suitable for field testing.