To accurately analysis and improve the performance of abrasive flow machining (AFM) in machining complex and special-shaped channel-parts, this study carried on a digital twin analysis, integrated with numerical and experimental approaches of cycloid special-shaped inner curved workpieces. The different sub-grid models are analysed and compared through large eddy simulation (LES), and the influence of processing factors is explored via the simulation and verified through experiments. The numerical results show that the dynamic kinetic energy sub-grid scale model can reflect the turbulent characteristics in the channel more accurately. The orthogonal test results show that the workpiece surface quality under AFM is greatly improved, and the surface roughness is reduced from 1.635 μm to 0.305 μm under the best combination of processing parameters. It reveals the fundamental behaviour of surface material removal and provide basis for the AFM processing of the special-shaped inner surface polished.