The invention discloses a coal mine underground temperature measuring drill rod based on a temperature measuring optical fiber and a using method thereof. The drill rod comprises a drill rod body withthe interior communicated, wherein the end of the first end of the drill rod body is open; a detachable sealing part for blocking an opening is arranged at the opening of the second end of the drillrod body; a guide hole for the temperature measuring optical fiber to freely penetrate through is formed in the side wall of the second end or the sealing part; the free end, stretching into the drillrod body, of the temperature measuring optical fiber is detachably connected with a push block with the size smaller than the inner diameter of the drill rod body; the effective sectional area of thepush block accounts for 80% -95% of the sectional area of the inner diameter of the drill rod body; and a high-pressure fluid inlet pressurizing opening is formed in the side wall of the second end or the sealing part and communicated with an external fluid pressure source. According to the drill rod of the special structure, an optical fiber temperature measurer and the temperature measuring optical fiber are combined, the position of a high-temperature coal seam is determined by actually detecting the peak position of the temperature in a drill hole, meanwhile, drilling can be conducted, and multiple purposes of one drill rod are achieved.