探针针尖曲率半径是影响原子力显微镜分析与观测精度的关键要素之一,微小光学零件采用的精密测量技术不适于分析非透明探针针尖曲率半径。以高分辨率扫描电子显微镜图像为分析对象,采用灰质化、滤波降噪等图像预处理和Canny边缘检测技术获取针尖轮廓,对轮廓坐标采样后利用非线性高阶多项式函数拟合轮廓曲线,根据扫描电镜图像的度量标尺换算得到针尖实际曲率半径。结果表明:该方法对AFM探针针尖曲率半径的测量偏差不超过15%,具有较高测试精度和广泛应用前景。 The radius of probe tip curvature is one of the key factors that affect the accuracy of AFM analysis and observation. The precision measurement technology used in micro-optical components is not suitable for analyzing the radius of curvature of non-transparent probe tip. High-resolution scanning electron microscope image was used as the analysis object. The contour of the tip was obtained by image preprocessing such as gray matter, filter noise reduction and Canny edge detection. After the contour coordinates were sampled, the contour curve was fitted by nonlinear high-order polynomial function. Scanning electron microscopy of the metric ruler converted to the actual radius of curvature. The results show that the method can not deviate more than 15% from the AFM probe tip radius of curvature, which has higher testing accuracy and wider application prospect.