Tower inclination is one of the important parameters to be considered when designing and maintain the transmission line. It has great value to realize accurate measurement and digital description of tower inclination with portably and high efficiency. Considering the deficiency of existing measurement methods and the feature of terrestrial 3D lidar, a new method to measure the tower inclination based on terrestrial 3D lidar is proposed in the paper, and a testing system is established. The field feasibility test and comparison test are carried out based on the developed test system. The test results show that accurate measurement of tower inclination can be realized with less field labor, and its measuring accuracy is as good as total station’s which can meet the needs of the engineering survey. The measurement result can be presented with visualization and digitization by 3D modeling of target object based on terrestrial 3D lidar. This method makes it easy to keep in the archives, to retrospect and to check. What’s more, the developed test system can be used when doing the actual engineering survey.