The finite element model of the structure of composited elastic metal sealing ring was established by using ANSYS Workbench software. The influences on the maximum Von Mises stress,the size and distribution of the seal contact pressure resulted from the changes of operation parameters such as the initial compression,working pressure were analyzed. The results show that top piece and the sealing piece of the composited elastic metal sealing ring are not completely contact when without working pressure,and the composited elastic metal sealing ring can not play a sealing effect.But in working conditions,the top piece and the sealing piece are completely contact when in a certain precompression,and the composited elastic metal sealing ring meets the sealing requirements.Appropriate increasing of precompression can improve the sealing performance of the sealing ring,but the maximum Von Mises stress is also increased,when the maximum Mises Von stress is greater than the yield limit of the material,the sealing ring will fail.The safe working angle range of the elastic sheet was calculated,which provided the basis for the design,installation and use of the composited elastic metal sealing ring.