The function of the existing simulation software is not enough to support the overall design requirements of the integrated photodetection system of the world.There is an urgent need to develop a simulation design software for photodetection scenes.Through the analysis of the components of the photodetection scene,the detection link and the task model,the structure,function and key technologies of the simulation system are planned.The properties and methods of object-oriented data structure and software simulation calculation flow are designed.The photodetection scene simulation software version 1.0 is developed in VS2010 + QT5.4 environment.The calculation results of the midcourse target detection mission by the STSS space-based infrared monitoring system are given.The main application results of the photodetection simulation technology of the author team are introduced.