To improve the endurance and reliability of cylindrical roller bearings (CRBs) under complex operating conditions, a dynamic model of CRB is developed. The model incorporates a roller–raceway contact model to optimize roller profile and is further verified with published data. Systematic parametric analyses are conducted to investigate the influence of flange angle, roller-end sphere radius, and roller profile on load distribution, roller tilt, roller skew, and contact performance. The results suggest that high flange–roller contact location and contact stiffness can effectively extend fatigue life of the bearing, while low flange–roller contact location can reduce the heat generation. In addition, roller profile has negligible effect on load distribution, but an optimized roller profile can improve the anti-tilt capacity. The developed model provides a tool for the internal design and frictional loss optimization of CRB under combined loads.