The purpose of this study was to investigate the effect of magnetic abrasive finishing(MAF) process parameters on the inner surface roughness of Ni-Ti alloy cardiovascular stent tubes. An experimental equipment for magnetic particle grinding processing of the inner wall of the Ni-Ti alloy cardiovascular stent tubes was established. The magnetic particle finishing processing of the inner wall of the Ni-Ti alloy cardiovascular stent tubes with inner diameter of 1.0 mm, outer diameter of 1.2 mm and length of 1800~2000 mm was carried out with the iron-based diamond magnetic abrasive prepareds(MAPs) by the preparation method of free-falling gas-solid two-phase flow two-stage atomization and quick-setting magnetic abrasive. Taking the surface roughness as the evaluation index, a response surface experiment with 4 factors and 3 levels was designed to explore the influence of pipe rotation speed, feed velocity of magnetic poles, magnetic abrasive filling quantity and size of diamond MAPs on the surface roughness and their interaction relationship, and a regression model of four process parameters on the surface roughness model was established. The process parameters were optimized by Design-Expect 12 software, and the optimal combination of process parameters was obtained. The accuracy of the regression model was verified by experiments. According to the response surface analysis results, the interaction effects of pipe rotation speed and feed velocity of magnetic poles, pipe rotation speed and magnetic abrasive filling quantity, and pipe rotation speed and size of diamond MAPs on surface roughness are significant. Surface roughness was taken as the evaluation index, and the influencing factors of each process parameter on surface roughness were sorted as follows:pipe rotation speed > feed velocity of magnetic poles > magnetic abrasive filling quantity > size of diamond MAPs. Taking the minimum surface roughness value as the goal, the combination of process parameters was obtained as follows:pipe rotation speed 100 r/min, feed velocity of magnetic poles 5 mm/min, magnetic abrasive filling quantity 0.1 g and size of diamond MAPs 100 μm. The predicted surface roughness Ra is 0.101 μm and the actual surface roughness Ra is 0.112 μm, and the error between the actual value and the predicted value is 10.9%. The inner wall of Ni-Ti alloy cardiovascular stents was finished by magnetic abrasive finishing method, which solved the problem of finishing the inner wall of the ultra-fine and ultra-long Ni-Ti alloy cardiovascular stents. Response surface methodology (RSM) was used to optimize the process parameters of magnetic abrasive finishing of the inner wall of the Ni-Ti alloy cardiovascular stents. The established surface roughness model has good prediction ability and has guiding significance for practical engineering application.