In this paper, we propose a method to measure the orbital angular momentum (OAM) modes of vortex beams using cubic phase gratings. Combining the unique phase change characteristics of the Airy beam with the structure function of the grating, a cubic phase grating is designed, and the vortex beam is collimated and incident on different incident points of the cubic phase grating to generate a diffraction pattern. The numerical simulation and experimental results show that the OAM mode of the incident beam can be easily measured by analyzing the Hermite-Gaussian diffraction pattern in the diffraction pattern. The topological charge of the incident beam is determined by the number of bright fringes in the diffraction pattern, and its positive and negative values are determined by the distribution trend of bright fringes. The optimized experimental link can simplify the experimental operation, the effect is obvious, and the topological load value detected can be reached up to 60.