The invention discloses a probe rod. The probe rod is used for detecting the water of oil stored in an oil tank, and comprises a micro water transmitter, a pipe body, a water induction sensor and a data line, wherein the micro water transmitter is fixed on the pipe body, the water induction sensor is arranged at one end of the pipe body, the water induction sensor is in sealed connection with the pipe body through a sealing device, one end of the date line is connected with the water induction sensor, the connection of the data line and the water induction sensor is positioned in the sealing device, and the data line traverses through the pipe body, traverses out from the other end of the pipe body, and is connected with the micro water transmitter. When the probe rod is used, the micro water transmitter is connected with a data collection device to provide convenience for subsequent data transmission, the water induction sensor goes through the pipe body, then is sent to the oil tank and acquires the data, and the pipe body has certain length, so the problem of uncertain uniform distribution of micro water close to a selected measurement port is solved, and real-time detection is realized.