The invention discloses a power transmission line tower lightning strike risk evaluation method based on the data mining technology. The power transmission line tower lightning strike risk evaluation method based on the data mining technology comprises the steps that the coordinates of a power transmission line tower, the structure information of the tower and insulating configuration information are input into a GIS, and the elevation information around the tower and the cloud-to-ground lightning density degree of the position where the tower is located are extracted by means of the GIS; topographic feature parameters are calculated according to the elevation information; calculation is conducted according to the coordinates of the tower, the structure of the tower and the insulating configuration information, so that a predicted value of the lightning strike trip-out rate of the tower is obtained. The power transmission line tower lightning strike risk evaluation method based on the data mining technology is characterized by further comprising the steps that the obtained topographic feature parameters of the tower, the obtained cloud-to-ground lightning density degree, the obtained predicted value of the lightning strike trip-out rate and obtained lightning strike trip records are input by means of data mining software, a data mining model is established, and the probability of lightning strike trips of the base tower is analyzed and output; the lightning strike trip probability of the tower is compared with the lightning strike trip probability of a tower to which lightning strike strips happen once, so that the lightning strike trip risk grade of the tower is evaluated, and reliable data support is provided for lightning protection design of a power transmission line and lightning protection differentiation transformation of the power transmission line.