The invention relates to a transmission line damage prevention early warning system based on the multi-sensor fusion technology and belongs to the power grid protection technology field. The early warning system comprises an onsite power source unit, an information acquisition unit, an alarm unit and a main server used for carrying out remote operation, wherein the main server realizes remote information transmission with the information acquisition unit and the alarm unit through the wireless network, the information acquisition unit comprises a laser detector and a video monitor on a pole and a supersonic wave detector hung and fixed on a transmission line, and the alarm unit comprises a high pitch alarm device on the pole and a sound-light alarm device on the transmission line. According to the early warning system, integrated information acquisition is carried out by utilizing multiple types of sensors, accuracy for information acquisition of objects entering a dangerous zone is greatly improved, dangers are eliminated before generation, and effective early warning and driving effects for the objects entering the dangerous zone are realized.