According to GB150—1998 Steel Pressure Vessels,JB4732—1995 Steel Pressure Vessels——Code of Analyzing Design and other country's codes,the design procedures and deficiency of the present codes have firstly been summarized in this paper,and a new design method of pressure vessel,dimensionless design method,then has been put forward. By the example of plane cover in fastener structure,the calculation and application procedure are given.