The utility model provides a spherical mill shoe. The spherical mill shoe comprises a cylindrical body and a mill shoe part. An upper connector used for being connected with a drill rod is arranged at the upper end of the cylindrical body. The mill shoe part is connected with the lower end of the cylindrical body, and the inner diameter of the mill shoe part is gradually reduced from bottom to top. The mill shoe part is semi-spherical and mill teeth are arranged on the semi-spherical inner wall. According to the utility model, through the semi-spherical inner wall of the mill shoe part, when tubular metal fallen-objects in a milling well is fished, the tops of the tubular metal fallen-objects can be wholly covered and located in the middle constantly, and therefore when the tubular metal fallen-objects in the well are repaired, the tops will be protected against eccentric wear.