Abstract: To investigate the influence of abrasive flow machining parameters on the surface quality of internal flow channels, the abrasive flow process was simulated using Fluent to analyze the effects of extrusion pressure, abrasive particle size, and concentration on flow field characteristics. Feature components with a convergent-divergent channel structure was designed, and an L₉(3⁴) orthogonal experiment was conducted. Range analysis was employed to determine the significance of each parameter. The results show that defects such as adhered powder, step effects, and balling on the workpiece surface were effectively eliminated after finishing. The surface roughness Ra was reduced from 7.0 to below 0.7 μm, and Rp was reduced from 21.00 μm to below 1.25 μm. The significance order of the parameters on surface quality was determined as processing time, extrusion pressure, and abrasive concentration. This study reveals the polishing mechanism of abrasive flow finishing and provides a reliable process solution and theoretical support for surface quality control of high-performance components with internal channels.