The work aims to remove carbon deposition from the inner wall of aero-engine turbo shaft. Magnetic needle grinding method was used to remove the carbon deposition on the inner wall of the turbo shaft. The surface morphology of the inner wall of the turbo shaft before and after removal of carbon deposition by grinding was observed by 3D ultra depth of field electron microscope. Scanning electron microscope was used to measure and analyze the components of carbon deposition on the inner wall of turbo shaft and the matrix components of turbo shaft. At the same time, the composition of inner wall of turbo shaft after the removal of carbon deposition by magnetic needle grinding was determined and compared with the matrix composition, to verify the thoroughness of carbon deposition removal. Carbon deposition on the inner wall of turbo shaft was completely removed by magnetic needle grinding. The elements in the carbon deposition were O, C, Na, Al, Si, Ti, Fe, Zr, Mo、S and K, and the elements in the matrix were C, Al, Si, Ti, Zr and Mo. The elements on the inner wall of the turbo shaft were C, Al, Si, Ti, Mo, O and Fe measured after removal of carbon deposition with magnetic needle grinding, showing that the carbon deposition on the inner wall of the turbo shaft was completely removed after magnetic needle grinding. The results of composition analysis show that this result is correct that the carbon deposition on the inner wall of turbo shaft obtained from surface topography analysis is completely removed. At the same time, it shows that the method of removing carbon deposition on the inner wall of turbo shaft by magnetic needle grinding is feasible and achieves good results.