The two-way fluid-solid interaction model of rotating ring-fluid film-stationary ring was established in hydrodynamic mechanical seal. Unsteady simulations were carried on at the upstream pumping state. The transient characteristics of the deformation of sealing ring and the pressure of the fluid film were studied

and the influence of the end face deformation on the pressure fluctuation was discussed by comparing the results before and after fluid-solid interaction. The results show that comparing the simulation without the deformation

the results obtained by fluid-solid-interaction are more realistic. The end face deformations of stationary ring is fluctuating like pressure fluctuation with same period

and the closer to the outlet at the inner diameter

the greater degree of the deformation fluctuation. The degree of pressure fluctuation is from big to small from inner diameter to outer. The end face deformation of sealing ring affects the pressure fluctuation slightly at the outer diameter

while enhances the pressure fluctuation at the inner diameter obviously

and the degree of the enhancement is greater with the increase of rotational speed

the influence of the sealing medium pressure is not obvious under the low pressure condition after fluid-solid interaction. The end face deformation of the sealing ring only affects the degree of the pressure fluctuation without changing the frequency of the pressure fluctuation.