To further explore the effect mechanism of the inclined-straight groove on the sealing performances,the hydrodynamic lubrication model of the liquid-film seal with inclined-straight groove was established based on the boundary of mass conservation and the liquid film density ratio defined.The finite difference method was adopted to discretize the equation,and the theoretical and experimental values of cavitation zone in the liquid film were compared and analyzed to verify the accuracy of the calculated model and program.The influences of structure parameters of inclined-straight groove on the sealing performances were investigated，including groove number,groove depth,radial and circumferential groove width ratios.Results show that within the critical range under different slant angles,increasing the groove number or groove depth is helpful to improve the liquid-film load-carrying capacity,increase the leakage and effectively reduce the liquid-film cavitation zone,especially under the condition of larger slant angles.In a certain range,although increasing the radial and circumferential groove width ratios can enhance the liquid-film load-carrying capacity,promote the cavitation occurrence,and increase leakage,the influence laws are not the same.With the liquid-film load-carrying capacity as the improvement goal,the optimal groove parameters are as follows:groove number 42,groove depth 25 μm,radial and circumferential groove width ratio 0.7 and 0.6,respectively.