With a history of about 150 years, photogrammetry technology has undergone profound changes with the development of computer technology and digital camera technology. Its development process has gone through three stages of simulation, analysis and digital photography. Initially it was applied to high-end aviation, aerospace, etc. In the field of measurement, map information or geographic information on the surface of the earth is obtained. At present, due to the substantial reduction in the price of computer hardware and digital cameras, the application of this technology has gradually extended to the industrial field to measure industrial products and their parts. Compared with aerospace vision photography In terms of measurement, the resulting digital close-range photogrammetry technology. With the wide application of this technology, it will continue to mature and improve itself. Considering its broad prospects for future development and the nature of high-tech, we chose this research topic Photogrammetry is a branch of the subject of measurement. It is a measurement technique that calculates the spatial (three-dimensional) coordinate values of certain parts of the measured object from the data on the photos obtained by photography. Its ultimate goal is to use triangulation. Method to restore the depth information of the scene. Triangulation refers to a method in which the camera shoots the same scene point from two or more different directions, and uses the parallax of two or more photos to restore the depth information. To complete the calculation of the scene For the coordinate value of the midpoint, it is necessary to know the external position and internal parameters of the camera each time the camera is taken, but to know these, it is necessary to know the coordinate values of some points in the scene in advance, so that they are contradictory to each other. Solve this contradiction. The secret weapon (or core technology)-the group adjustment method can calculate both at the same time. The essence of the group adjustment method is to use the nonlinear square method to optimize all the parameters in the equation at the same time, so that the calculation can be calculated from each photo Scene coordinate value and estimation