Far-field laser spot intensity distribution measuring device and measuring method

The invention discloses a far-field laser spot intensity distribution measuring device, which comprises a fixed diffuse reflection plane, a movable diffuse reflection plane, a spot camera, a one-dimensional translation sliding table and a control and data processing computer, and is characterized in that the diffuse reflection plane and the diffuse reflection plane are parallel to each other and are vertical to the optical axis of the spot camera; the light spot camera is connected with the control and data processing computer, the control and data processing computer controls the light spot camera to carry out light spot imaging, and light spot intensity distribution at the fixed diffuse reflection plane and the movable diffuse reflection plane is calculated through camera calibration results. Calculating a first moment of light spot intensity distribution, calculating a pitch angle and an azimuth angle of an incident light beam, and performing affine transformation on a measured oblique incident light spot