A kind of inner surface finishing machining device for slender tube was introduced, and the stress analysis was carried out, the calculation formula of the grinding force between grinding rods and the internal surface was deduced. MATLAB was used to build the mathematical modeling, the influences of related parameters on the grinding force were analyzed.Taking the stainless tube with inside diameter 54 mm and long 15 m as the example, the processing speed was 940 r/min, the device processing effect was verified by experiment. It provides theoretical and experimental basis for the next deeper research.