为了探测高精度的远场光斑质心，本文提出了一种多光斑质心探测方法。该方法利用二维正交的衍射光栅，将远场单光斑扩展为多光斑阵列，通过增加探测光斑的输入信息量，提高质心探测精度。实验结果表明，远场多光斑质心探测精度比单光斑质心探测精度提高了近4倍，单个光斑质心探测误差均方根(RMS)为0.0385 pixels，16个多光斑阵列平均质心探测误差RMS为0.0099 pixels。相对于传统的质心探测方法，本文所采用的远场多光斑质心探测方法更为简便。

In order to detect high-precision far-field spots centroid, a multiple spots centroid detecting method is proposed. Using two-dimension orthogonal diffraction gratings, a single spot on the far-field focal plane is developed into a multiple spots array. By increasing the input information of the far-field detected spots, the centroid detection accuracy can be improved. The experimental results show that the centroid detecting accuracy of multiple spots is 4 times larger than that of single spot. The root mean square (RMS) of single spot centroid detecting error is 0.0385 pixels and the RMS of 16 spots centroid detecting error is 0.0099 pixels. Compared with the conventional method of the centroid detecting, the far-field multiple spots centroid detecting method proposed is simpler and more convenient.