To study the surface integrity of the stainless steel closed integral bling in abrasive flow machining， single factor tests of processing time， processing pressure and abrasive mesh size are carried out on the stainless steel samples prepared by electrical discharge machining， and the influence of three factors on the surface integrity after machining is investigated. The surface roughness value Ra decreases with the increase of processing time， from 1.459 μm at the initial time to 0.193 μm at 60 min. The surface roughness decreases at a slower and slower rate， and finally tends to stabilize. The recast layer is effectively removed by abrasive flow machining， and the microhardness decreases from 450~950 HV to 270~350 HV after machining， and the distribution uniformity is improved. The microhardness decreases with the increase of processing time， and some work hardening occurs. The residual stress changes from tensile stress to compressive stress after abrasive flow machining with different mesh numbers of abrasives. With the increase of processing time and pressure， the smoother the sample surface is， the better the polishing effect will be.