In order to study the influence of rarefied gas effect on the static and dynamic characteristics of self-acting bearing with small clearance,the static and dynamic Reynolds equations considering rarefied gas effect were established respectively based on the finite volume method,by using the continuous model,the first-order slip model,as well as the Wu new slip model which is in good agreement with the solutions of linear Boltzmann equation under any Knudsen number.The relationship between static bearing capacity and eccentricity,and the relationship between disturbance frequency and dynamic characteristic coefficient of micro self-acting bearing under three models were given.The results of numerical analysis are as follows,with the change of eccentricity,the static bearing capacity predicted by the continuous model is the largest,the first order slip is the second,and the predicted value by the new WU slip model is the smallest.With the increase of disturbance frequency,the principal stiffness coefficient and principal damping coefficient calculated by the slip models tend to decrease,and the principal stiffness coefficient and principal damping coefficient calculated by the new WU slip model are obviously lower than those by the continuous model and the traditional firstorder slip model.The static and dynamic characteristic coefficients of bearings are overestimated by the traditional continuous model and the first-order slip model,and the results of the new WU slip model are more accurate.