TC4 titanium alloy is widely used in aerospace parts, medical equipment and automobile industry because of its good mechanical properties, large specific strength and low thermal conductivity. The operational demands within these sectors necessitate superior surface quality and minimal surface roughness, thereby imposing heightened prerequisites on the surface polishing procedures. Compared with the traditional air jet polishing process of hard abrasives, the use of composite abrasive polishing can make the workpiece get a more uniform surface and a lower surface roughness, and reduce the subsurface damage to the material surface while removing the material on the workpiece surface. In order to explore the effect of composite abrasives on the surface roughness and surface morphology of TC4 titanium alloy in the air jet polishing process, the work aims to use rubber as a superelastic matrix, and coat the surface of rubber particles with cryolite powder and 1 μm diamond particles in batches, so as to obtain a hyperelastic composite abrasive with a particle size of about 2 mm, a regular shape and a uniform surface abrasive adhesion. ABAQUS finite element simulation software was used to simulate the deformation and motion trajectory of the composite abrasive polishing process to explore the effect of abrasive incident angle and polishing pressure on the surface morphology and surface roughness of the material. The Mooney-Rivlin constitutive model was used to characterize the rubber matrix, and the corresponding incident angle and polishing pressure were simulated after setting of the corresponding incident angle and polishing pressure. Analysis of the results revealed that the incident angle of the abrasive affected the deformation and cutting force of the composite abrasive during polishing, while polishing pressure affected the slip distance of the composite abrasive on the material surface. The effects of incident angle, polishing pressure and polishing time on the surface of the composite abrasive were studied by single factor comparison method. The surface of the material was observed and characterized by super depth of field three-dimensional microscope, white light interferometer (Super View W1, Chotest, China), scanning electron microscope (SEM) (ΣIGMA, ZEISS, Germany). Finally, it is concluded that TC4 titanium alloy can get lower surface roughness and more uniform surface morphology when the abrasive incident angle is 20°, the polishing pressure is 0.5 MPa and the polishing time is 2 min. Furthermore, the material removal rate under different abrasive incident angles and polishing pressure is calculated by measuring the mass change before and after polishing, aiming to characterize removal efficiency and machining accuracy under varying process parameters. The surface quality is further analyzed by surface skewness and kurtosis. However, after 6 to 8 cycles, the diamond abrasive layer will be damaged and peeled off due to the continuous collision between the surface diamond abrasive layer and the titanium alloy surface. In order not to affect the final polishing effect, it is necessary to repair the composite abrasive and coat the surface with diamond abrasive particles to obtain a uniform diamond abrasive layer.