3D LIDAR in China has a huge market, but foreign commercial 3D LIDAR is very expensive. So a 360° continuous scanning, portable 3D LIDAR system is developed. A 2D laser scanner (SICK LMS200) is selected to combine with an additional step drive to reach a 3D sensor. The sources of systemic errors are analyzed, a method of error correction is proposed, and the accurate calculation formulas of 3D coordinates are given. The experimental results show that the system has higher measuring accuracy and data quality. The maximum range of the system is 80 m, measurement accuracy can achieve 6 mm. It can collect 7256 points in a second to meet the needs of fast capturing 3D data from indoor and outdoor scene, and then its cost is only 4 times lower than that of current commercial 3D laser scanners. It is easy to carry for small size and light weight.