The work aims to solve the problem of poor quality of machined titanium alloy surface. Surface finishing was conducted to TC11 titanium alloy by virtue of magnetic abrasive process. Effects of process parameters of magnetic abrasive finishing on surface quality of titanium alloy was studied with surface roughness as the main evaluation criteria, and process parameters were optimized on this basis. Surface finishing was conducted by using the optimized process parameters, to study the influence of magnetic abrasive process on microstructure of titanium alloy. When the machining clearance was 3 mm, the grinding pressure was appropriate and the surface roughness of machined workpiece was the minimum; when abrasive grain in 100 meshes was used, the surface texture was fine, surface roughness value was the minimum; provided that the spindle speed and surface material removal rate of the workpiece increased, surface roughness value of the machined workpiece was the minimum at the spindle speed of 1500 r/min; compared with metallographic structure of the workpiece before machining, the microstructure grain was refined, grain boundaries increased, and the surface tensile stress of workpiece became compressive stress. The experiments have determined the optimal process parameters combination, namely: machining clearance of 3 mm, magnetic abrasive size of 100 meshes and spindle speed of 100 r/min. Permanent magnetic abrasive process can greatly reduce the surface roughness and improve surface microstructure of TC11 titanium alloy.?