One-dimensional dynamic method was used to calculate multi-working cases of an engine idle gear bearing.From four factors of oil holes layout,load direction,load size and bearing speed,the variation rules of four sliding bearing hydrodynamic characteristics,including oil flow rate,minimum oil film thickness,offset angle and maximum oil film pressure,were analyzed.The results show that the oil hole layout and load direction mainly affect the oil flow rate,but have little influence on the other three hydrodynamic characteristics.The more oil holes there are,the closer the oil holes are to the point with the highest oil film thickness in the circumferential direction,the greater the lubricating oil flow rate.The more uniformly the oil holes distribute,the smaller the flow fluctuation caused by the change of load direction.The load and bearing speed have obvious influence on the four hydrodynamic characteristics.With the increase of load,the maximum oil film pressure increases linearly,while the change rate of the other three characteristics decrease gradually.With the increase of rotational speed,the decrease rate of maximum oil film pressure is reduces,and the other three characteristics increase linearly.