Petrochemical structures are often characterized by uneven distribution of stiffness due to the complicated arrangement of its equipment pipelines，and designs are often overly conservative.In order to analysis of the steel frame structure based on displacement，the finite element software was used to model，calculate and analyze the steel frame structure of refining platform.In the PDS（the probability design system）module，the Monte Carlo method was used to analyze the reliability of structural displacement in the PDS module to obtain the calculation results of the relationship between the maximum displacement and the random input variables of the steel frame structure of the refining platform.The results revealed that the section size of the steel frame structure was more conservative，resulting in the waste of steel.In order to realize the design of the structures economy，we should optimize and redesign the crosssectional dimensions of nonsensitive factors in the graph based on the calculated sensitivity diagram to meet the structural reliability，and draw a safe and economical design plan for the future petrochemical industry，which could provide reference for the future design of steel frame structure in petrochemical industry.