Low-cost 3D scanning systems integrating single-line LiDAR with mechanical actuators have been widely applied in field robotics. Structural imperfections in the LiDAR actuation mechanism often introduce systematic errors, typically arising from rotational axis misalignment. These errors distort point clouds and degrade reconstruction accuracy. This paper proposes a geometric fitting-based calibration method, compensating for translational and angular deviations. The method estimates and corrects systematic errors through distorted boundary fitting. Experimental results validate the method’s effectiveness and practicality in improving reconstruction accuracy.