Abstract: Natural gas database is established by GERG-2004 equation which is very comprehensive and accurate in the field of natural gas application at present.Interpolation algorithm is defined by user FORTRAN program,VBA macro language and MATLAB.Physical property data in database is called in the numerical simulation of CFX.This paper takes the natural gas labyrinth type valve as an example,calling physical property data in the numerical simulation based on k-Epsilon flow model,completing the simulation of labyrinth control valve using natural gas as medium,which provides a solution for the simulation of over-current components with natural gas as medium.