The utility model discloses an unmanned aerial vehicle forest height of tree monitoring system based on liDAR technique relates to forest height of the tree and biomass monitoring field. The utility model discloses an use the unmanned aerial vehicle data acquisition system of the unmanned aerial vehicle constitution of lift -launch laser radar for scanning equipment, point cloud data and image data transmission to the ground center that to gather, generate high accuracy DEM achievement fast at the ground center, high accuracy DOM achievement, wood land three -dimensional model, forest height of the tree draws the result, supply further to do inverting of forest biomass and monitoring aassessment, show the precision that has improved regional forest height of the tree and biomass estimation, and the time of having broken through, space and weather conditions's restriction.