Mechanical seal was often in dry friction state during start-up and stop stage or misoperation,and the resulting thermal damage and wear will affect its sealing performance.Taking a YWN8 alloy contact mechanical seal as the research object,a wear numerical model based on hardness and wear coefficient was established.The hardness,wear coefficient and dry friction coefficient of the seal ring of the friction pair were tested,and the accuracy of the wear numerical model was verified.The wear of mechanical seal was simulated,and the wear depth of seal ring of friction pair under single force field and thermal deformation during dry friction operation was studied,and the result was verified by wear theoretical value.The results show that the temperature rise of the end face of the seal ring is low during dry friction operation,and the temperature is not the main reason for its failure.After the thermal mechanical deformation,the clearance between the inner and outer diameter of the sealing ring increases,resulting in the reduction of the contact area of the rough peak of the end face,and the adhesive wear shows a downward trend compared with that before deformation,resulting in the wear depth in multiple physical fields inconsistent with the theoretical value.