The multibody model of bellowsdynamic ringfluid filmstatic ring of bellows mechanical seal was established. Numerical calculation and analysis of thermofluidsolid coupling on sealing interface were carried out under high temperature, high pressure and high speed, and the stress and strain law of the seal ring under the coupling effect of temperaturevelocitypressure field were obtained. On this basis, the influence laws of the spindle speed and fluid pressure difference on the temperature rise and thermal stress deformation of sealing ring end face were analyzed. The results show that the maximum deformation of the seal ring is at the inner diameter of the end face, and the deformation decreases from the inside to the outside; the temperature rise of the dynamic ring end face increases almost linearly with the increase of the sealing pressure and the rotation speed of the rotating shaft; the thermal deformation of the dynamic ring increases with the increase of the rotating shaft rotation speed and the sealing pressure.