An engine crankshaft was investigated. The finite element method, dynamics method and lubrication theory were used to analyze the dynamic stress distribution of the crankshaft. At the same time, the nonlinear spring (NONL), dynamic hydraulic lubrication (HD) and elastic dynamic hydraulic lubrication (EHD) were used to analyze the crankshaft stress. Some parameters that influence on the stress distribution of the crankshaft were analyzed. The results showed that the stress distribution of crankshaft was different under different calculation models, because the torsional vibration and bending were different. At the same time, the stress caused by the contribution of torsional vibration and bending vibration in different sections at different times was different. Oil groove were also studied to investigate the influence that these parameters on the stress distribution based on the EHD model. It had little influence on the stress distribution. The value range was only -2.5~2.5MPa.