In order to discuss the effects of different rheological models on the minimum film thickness and central film thickness，ReeEyring fluid,BairWiner fluid and Carreau fluid were selected and non Newtonian fluid elastohydrodynamic lubrication model was established.The influence of environmental viscosity on oil film pressure and film thickness was explored.The results demonstrate that the minimum film thickness calculated by the Carreau rheological model is most consistent with the measured result.Compared with Newton fluid model,the higher center oil film thickness is obtained based on Carreau and ReeEyring rheological models,and the highest center oil film thickness is obtained based on Carreau model,the minimum film thickness is obtained based on BairWiner rheological model.Compared with the Roelands model,a lower viscosity in the central region produced by the Doolittle free volume viscosity model.The oil film thickness is increased with high ambient viscosity,and the peak value of the second pressure is also increased.