Based on the existing numerical calculation method for isothermal elliptical contact elastohydrodynamic lubrication,the influence of the variation of film thickness constant ΔH on the relative accuracy of pressure iteration was analyzed by using the Newton finite difference method.It is found that when the initial value of ΔH is 10% of the minimum film thickness,within a certain range,the smaller the change period and the larger the reduction range of ΔH,the smaller the relative precision.After setting a reasonable variation of ΔH,when judging that the convergence accuracy of pressure tends to be stable,the partial influence of iteration method can be neutralized by enlarging ΔH at the minimum of relative accuracy.It can satisfy the convergence condition at the lowest point to complete the numerical calculation,avoid falling into the dead cycle and improve the calculation efficiency.