Measurement method for transient wavefront distortion for beam shaping element in online situation

The invention relates to a measurement method for a transient wavefront distortion for a beam shaping element in an online situation, and belongs to the technical field of the wavefront distortion measurement. The method comprises the following steps of: obtaining a reference spot image firstly; and then acquiring an actual light spot image corresponding to an incident light beam; selecting a subaperture area; comparing the actual light spot image with the reference light spot image, so that a corresponding relative offset in each sub-aperture area is obtained, and a local wavefront slope ofthe incident light beam is obtained; and finally, completing the unknown wavefront distortion measurement in the incident beam by using the wavefront reconstruction algorithm. According to the measurement method for the transient wavefront distortion for the beam shaping element in online situation, the method can separate the coupling influence between the wavefront distortion of the incident beam and the modulation of th