A method for measuring a hole provided in a workpiece is provided and the method comprises: obtaining a three-dimensional point cloud model of the workpiece and a two-dimensional image of the workpiece, defining a first contour in the three-dimensional point cloud model based on an intensity difference of the two-dimensional image, defining a second contour and a third contour respectively based in the first contour, bounding a data point testing region between the second contour and the third contour, respectively defining data point sampling regions along a plurality of cross-section directions of the data point testing region, respectively sampling data points in the data point sampling regions to obtain a turning point set comprising turning points, wherein each of the turning points has the largest turning margin, connecting the turning points which are distributed in the turning point set along a ring direction to obtain an edge of the hole.