Temperature calculation is a prerequisite for infrared radiation simulation, which is widely applied in the military field. However, conventional sequential temperature computation approaches are computationally inefficient and inadequate with regard to thermal details. A method of parallel temperature calculation based on OptiX is proposed to solve this problem. First, a brief introduction to OptiX is given, and its abilities to implement parallel temperature calculation and infrared scene simulation are demonstrated. As the foundation of the temperature calculation, the one-dimensional thermal conduction equation and boundary conditions of the natural scene are then described. After that the basic equations are generalized to the case of multilayer materials. Finally, the relationship between the geometric models and relevant material properties is articulated to facilitate the temperature calculation procedure. The results show that the developed platform is feasible for parallel temperature calculation, and qualitative analysis is preliminarily presented to substantiate the rationality of the simulation result.