A feature-point three-dimensional measuring system of a planar array of identical digital cameras arranged in two or more pairs such as to form one or more four-camera group of four cameras, wherein each four-camera group is arranged in a form of a 2x2 array, in the case that one pair of cameras is adjacent to two other pairs of cameras in the horizontal or vertical direction, this pair of cameras is part of two four-camera groups formed respectively by this pair of camera and each of the two other adjacent pairs of cameras; each four-camera group comprises a camera a, a camera b, a camera c, and a camera d, wherein the camera a, the camera b, the camera c, and the camera d are arranged on a same plane; focal points O a, O b, O c, and O d on imaging optical axes of the four cameras, the camera a, the camera b, the camera c, and the camera d, are on a same plane and form one rectangular shape, forming a rectangular plane; all of imaging optical axis central lines of the four cameras, the camera a, the camera b, the camera c, and the camera d, are perpendicular to the rectangular plane; the four cameras, the camera a, the camera b, the camera c, and the camera d, are of identical models and have identical lenses; the camera a is located on a position horizontal to the camera b, and the camera c is located on a position horizontal to the camera d; the camera a is located on a position vertical to the camera c and the camera b is located on a position vertical to the camera d; the four cameras have overlapping field of views such that the measured object can simultaneously have corresponding imaging points on the four cameras; wherein the feature-point three-dimensional measuring system further comprises at least one vertical laser and at least one horizontal laser, wherein the vertical laser is configured to be located on a perpendicular bisector of a connecting line of O a and O b, and the horizontal laser is configured to be located on a perpendicular bisector of a connecting line of O a and O c. each four-camera group is arranged in a form of a 2x2 array, in the case that one pair of cameras is adjacent to two other pairs of cameras in the horizontal or vertical direction, this pair of cameras is part of two four-camera groups formed respectively by this pair of camera and each of the two other adjacent pairs of cameras; each four-camera group comprises a camera a, a camera b, a camera c, and a camera d, wherein the camera a, the camera b, the camera c, and the camera d are arranged on a same plane; focal points O a, O b, O c, and O d on imaging optical axes of the four cameras, the camera a, the camera b, the camera c, and the camera d, are on a same plane and form one rectangular shape, forming a rectangular plane; all of imaging optical axis central lines of the four cameras, the camera a, the camera b, the camera c, and the camera d, are perpendicular to the rectangular plane; the four cameras, the camera a, the camera b, the camera c, and the camera d, are of identical models and have identical lenses; the camera a is located on a position horizontal to the camera b, and the camera c is located on a position horizontal to the camera d; the camera a is located on a position vertical to the camera c and the camera b is located on a position vertical to the camera d; the four cameras have overlapping field of views such that the measured object can simultaneously have corresponding imaging points on the four cameras; wherein the feature-point three-dimensional measuring system further comprises at least one vertical laser and at least one horizontal laser, wherein the vertical laser is configured to be located on a perpendicular bisector of a connecting line of O a and O b, and the horizontal laser is configured to be located on a perpendicular bisector of a connecting line of O a and O c.