Abstract: The boundary layer edge conditions were determined by 3-D CFD(Computational fluid dynamics) method and solved by 3-D Euler equation on structured grids;the wall stream trace was computed based on the stream function theory and flow parameters;the heating rates of staypoint with constant and variable specific heats were computed by the theory and semi-experienced formulas,while the heating predictions of non-staypoint were calculated based on the reference enthalpy theory and locally similar theory.The calculated results of the heating rates of double blunt biconic are in good agreement with existing experimental data and classic engineering methods,with average precision about 10%.It is applicable to the parametric design of hypersonic aircrafts.