Abstract: A to-be-measured partially coherent fractional vortex beam passes through a scattering object, an error between measurable information and to-be-measured information is minimized by using an optimization algorithm, and a main electric field mode and a weight of a to-be-measured fractional vortex beam are reconstructed by using a multimode stacked diffraction algorithm. A cross-spectral density function of the partially coherent fractional vortex beam is calculated, a cross-spectral density of a partially coherent fractional vortex optical field is reconstructed, and complete information including light intensity, a light intensity association, an electric field association, a phase, and the like of the partially coherent fractional vortex optical field is obtained.