For the reliability of design and operation of high pressure cylinder,finite element analysis program is used to analyze temperature,thermal stress,mechanical stress and total stress for high pressure inner and outer cylinder of supercritical 1 000 MW steam turbine at normal operating conditions.The results of analyzing inner and outer cylinders respectively are compared with the results of combined inner and outer cylinders.The comprehensive data of temperature and stress for the high pressure cylinder are presented,which provide important technical basis for safety evaluation and life estimation of steam turbine.