The relationship between the cage slip ratio and characteristic frequencies was obtained by theoretical deduction. The correctness of the derivation formulas was verified by the rotor experiment bench supported by cylindrical roller bearings. And the variation law of the slip ratio of the cage

the actual characteristic frequencies and the theoretical values deviations with the rotational speed were studied. Results showed that the slip ratio and the deviation tended to increase with the growth of the shaft rotating speed. The research conclusion has the guiding significance for the fault diagnosis of the aeroengine main-bearings.