Abstract: The 3D scanner has been widely used in 3D scene reconstruction, intelligent manufacturing, automatic driving, virtual reality and other fields due to its advantages of high accuracy, fast speed, automatic processing and good stability. At present, most 3D scanners are installed on tripods, which is easy to cause an angle between the rotation axis of the scanner and gravity direction due to uneven ground. Therefore, the panorama and point cloud are skewed, which is a key problem affecting the accuracy of 3D reconstruction. To solve this problem, a method to calibrate the tilt angle of 3D scanner by using inertial measurement unit (IMU) was proposed. The proposed method used the acceleration information output by IMU to establish the connection between IMU and 3D scanner through an area array camera. The acceleration information of IMU was transferred to the central axis of scanner. Using the transferred information to calculate the angle between the rotation axis of scanner and gravity direction, then compensating this tilt angle to the generated panorama and point cloud, and the skew model can be corrected. Through experiments to compare the calculated angles before and after the calibration, the experimental results show that the tilt angle measurement error can be controlled within 0.5°. And after calibration, the accuracy is increased by at least 20%, which verifies the reliability and accuracy of the entire calibration method.