The invention discloses a transmission corridor tree barrier monitoring system based on aerial remote sensing. The system relies on an airborne LiDAR (2) carried by an aerial vehicle (1) to carry outmultiple echo detection on surface trees and transmits the detection result to a ground data processing module (4) through a communication module (3), and a surface digital elevation model (DEM) and acanopy surface digital model (DSM) carries out analyzing and calculating to acquire regional tree height distribution data. The tree height data are input into a grid transmission GIS overlay analysis module (5) for overlay analysis to acquire the distance between trees in a transmission corridor and a transmission line. The overlay analysis result is input into a data management module (6) to implement data management of the distance between trees in the transmission corridor and the transmission line, wherein the distance changes with a time series. Comparing with the set early warning value of the safety distance of the transmission line is carried out, and if the early warning value is reached, a warning signal is sent immediately. A technical support is provided for the clearing of tree barriers in the transmission corridor.