Projection distortion correction method and system in optical surface shape compensation interference measurement and medium

The invention discloses a projection distortion correction method and system in optical surface shape compensation interference measurement and a medium. The projection distortion correction method comprises the steps of: building a measurement system optical model, and inserting a virtual reference spherical surface at a position confocal with a point light source; carrying out ray tracing, and respectively obtaining the abscissa {(xm, ym)} of the intersection point on a measured mirror surface corresponding to the entrance pupil coordinate grid rays and the abscissa {(xr, yr)} of the intersection point on the virtual reference spherical surface; calibrating the linear scale factor of the abscissa (xrt, yrt) on the virtual reference spherical surface corresponding to the pixel coordinate(u, v) on the image surface of an interferometer, and converting the pixel coordinate of the surface shape error distribution measured by the interferometer into the abscissa (xrt, yrt) on the virtualreference spherical surfa