Abstract: In order to design a 3-D galvanometric scanner with a large working field,its dynamic response capability,control algorithm and calibration algorithm were studied in detail. After selecting a servo motor with high dynamic response as the executive unit of the scanner,optimizing the scanning path and delay parameters,a 3-D scanner was developed successfully. A precise calibration model was designed to calibrate the scan image. This set of scanner was validated with it running for a long time. The scanner worked stably with repeating location precision of ≤30μm and scanning precision of 100mm ±0.1mm. The results show that the 3-D scanner has important application in large scanning fields.