Abstract:The flow-thermal coupling calculation of aero engine air system includes fluid network and thermal network. By conservation equation, results will be get by iterative calculation, after each iteration, the parameters will be amendment. This paper presents an idea of the parameter modification of coupling calculation. Considering the effect of fluid temperature increasing resulted from solid heat transfer, density is set as the modifying standard. And some parameters for flow-thermal coupling calculation can be get by the local three-dimensional simulation.