The invention provides a power transmission line intelligent inspection system based on LiDAR and further provides a power transmission line intelligent inspection method based on LiDAR. The power transmission line intelligent inspection system comprises a three-dimensional quantifying information acquiring unit, a three-dimensional rebuilding unit and an intelligent inspection analysis unit. The three-dimensional quantifying information acquiring unit is suitable for acquiring power transmission equipment actual space three-dimensional quantifying information and power transmission line peripheral environment ground feature three-dimensional quantifying information, namely, point cloud data provided by LiDAR; the three-dimensional rebuilding unit is suitable for three-dimensional rebuilding of a power transmission line body and a corridor based on power transmission equipment actual space three-dimensional quantifying distribution information and power transmission line peripheral environment ground feature actual three-dimensional quantifying information; the intelligent inspection analysis unit is suitable for carrying out safety distance detection based on three-dimensional rebuilding results, carrying out safety distance analysis according to safety distance detection results and power transmission line safety standards and pointing out power transmission lines not catering to the safety standards or giving an alarm about the power transmission lines not catering to the safety standards. By means of the power transmission line intelligent inspection system and the power transmission line intelligent inspection method, requirements for line inspection data and function digitalization, standardization and visualization are achieved.