Abstract: Thermal-hydraulic coupling code is important for reactor core design. In this paper, the reactor core of Qinshan-Ⅱ nuclear power plant was selected as study object. CASMO4E was used to calculate the assembly homogenized parameters. The sensitivity study of independent parameters used in thermal-hydraulic coupling code was finished. Two kinds of cross-section tables were established, and the error analysis of these two cross section tables was finished.