Skidding is one of the important factors affecting the life and reliability of rolling bearings. Rotational speed fluctuations which often happen in the actual operation process of rolling bearings have an important influence on the running state of rolling bearings. The interaction model between rolling elements and inner ring is built based on the Hertz contact theory and deformation-displacement compatibility condition, the interaction between rolling elements and cage is simulated by nonlinear springs, the skidding dynamic model of rolling bearing under rotational speed fluctuation condition is developed. Through comparisons with experiments results, the proposed model is verified. Based on the dynamic model, the influence of rotational speed fluctuation on skidding and skidding characteristics of rolling bearing under various factors such as rotational speed fluctuating amplitude and frequency are investigated. The results show that the rotational speed of the cage fluctuate and skidding occurs due to the fluctuation of bearing's speed, sliding mainly appears between rolling elements and inner race, the rotational speed fluctuating amplitude has a great effect on the skidding while the frequency has little influence. The results of this paper have great guiding significance and reference value for failure analysis and durable and reliable operation of rolling bearing.