In order to study the service life of the cross cylindrical roller slewing ring,the actual working condition was simulated by Romax,and the simulation model was established in Roamx software to study the contact stress,oil film thickness and service life of the slewing ring under different loads,radial working clearance and working temperature.The results show that with the increase of axial load,the contact stress is increased,the minimum oil film thickness is decreased,and the service life is decreased.There is an optimal axial load to make the slewing ring meet the service life requirements.When the radial working clearance increases from negative value to positive value,the contact stress is first decreased and then tends to be stable,the minimum oil film thickness is stable in a certain range,the service life is first increased and then tends to be stable and finally decreased.There is an optimal radial working clearance to meet the service life requirements of slewing ring.With the increase of working temperature,the oil film thickness is decreased gradually,the life is stable at the beginning,but decreases with the increase of temperature.There is a minimum oil film thickness that makes the slewing ring meet the service life requirements.