To research the radiation properties of heat flow around the aircrafts’ surface in hypersonic flight, a fusion algorithm to calculate the radiation of flow around hypersonic aircrafts is proposed in this paper. Firstly, the algorithm use the computational fluid dynamics (CFD) to calculate the basic aerodynamic parameters of the aircrafts which are inside boundary layer, such as pressure, density, etc. Subsequently, the model of the radiation of flow around aircrafts is built by using the engineering algorithm. Then, we can build the model of the radiation properties of heat flow around the surface of the aircrafts effectively. The result can reflect the distribution of the radiation of heat flow around surfaces of the aircrafts accurately, and provide data support to study its optical detection and thermal protection.