The work aims to improve the surface quality of nickel based alloy special-shaped tubes and reduce the surface roughness by machining the nickel based alloy special-shaped tubes with ultrasonic combined magnetic abrasive finishing and investigate the effects of ultrasonic frequency, ultrasonic amplitude and spindle speed on the inner wall surface quality and surface roughness of special-shaped tubes by response surface methodology. The axial ultrasonic vibration was added on the basis of the built-in auxiliary magnetic pole magnetic abrasive to promote the magnetic abrasive particles to scratch and carve the inner surface of the tube. The response surface method was used to design the 3-factor and 3-level method, and the three-dimensional mathematical model was set up to analyze the effects of ultrasonic frequency, ultrasonic amplitude and spindle speed on the surface quality and surface roughness of the inner wall of the special-shaped tube under two factors to obtain the best combination of parameters. The optimum design of response surface method was the best in the condition of ultrasonic frequency 19 kHz, ultrasonic amplitude 19 μm and spindle speed 1200 r/min. Under the optimized process parameters, the ultrasonic composite magnetic grinding test was carried out. After 30 min processing, the surface roughness of the inner wall of the pipe was reduced from original Ra 2.4 μm to Ra 0.31 μm. The residual tensile stress +49 MPa of tube was changed to residual compressive stress -47 MPa. The ultrasonic axial vibration is added on the basis of the auxiliary magnetic pole magnetic grinding, which makes the grinding particle roll up and the grinding track complicated and effectively improves the surface roughness of the inner wall of the pipe and the surface processing quality. The response surface method can optimize the mathematical modeling design of the test results and fit the best combination of the processing parameters. The good stress state effectively improves the fatigue strength of the workpiece.