激光光斑中心检测是光学测量中常用的关键技术。传统的检测算法如重心法、Hough 变换法等在检测精度或速度上存在不足。因此本文根据激光光斑的特性提出了一种基于图像分割的圆拟合定中算法，利用MATLAB图像处理技术，对原始图像进行增强、分割，从而找到最内圈的衍射环，将影响圆拟合精度的各种干扰因素减少到最小，可达到亚像素级的定位精度,而且具有很快的计算速度, 可适用于实时的光学测量。

The laser spot detection is the key technology used in the optical measurements. Traditional detection algorithms have some shortage in detection accuracy or speed such as the center of gravity method, Hough transform method. According to the characteristics of the laser spot a circle fitting given in the algorithm based on image segmentation, using MATLAB image processing technology, the original image enhancement, segmentation, in order to find the innermost diffraction rings. It can reduce the factors of the circle fitting accuracy for various confounders to a minimum. In this way, it will achieve sub-pixel positioning accuracy and fast calculation speed. It can be applied to real-time optical measurements in the end.