Due to the influence of machining roundness error,the contact stress distribution of the radial metal seal for the interval control valve is uneven.The contact stress distribution of the radial metal seal with roundness error was studied by finite element method,and the influence of roundness error on the contact stress of radial metal seals was analyzed.Based on the finite element analysis results,the theoretical analytical formula of contact stress distribution of radial metal seal was proposed,and the error was analyzed.The theoretical solution and numerical solution of the contact stress distribution on the radial metal seal lip with roundness error are consistent,and the average relative error of the maximum contact stress caused by each parameter is about 10%.A reasonable interference function based on the distribution law of contact stress in radial metal sealing pairs with roundness error was proposed,the theoretical relationship formula of contact stress in the cantilever beam model of radial metal sealing axisymmetric structure was corrected,and the distribution law of contact stress in radial metal sealing under roundness error was obtained.This research provides the theoretical guidance for the design of radial metal seal for the interval flow control valve.