The invention discloses a numerical simulation method for interaction of coal powder particles in burning, belonging to the technical field of computer numerical simulation. According to the characteristics of burning of the coal powder particles, the method is characterized in that on the basis of calculation of an existing mathematical model of fluid mechanics software FLUENT, FLUENT UDF and FLUENT Scheme are used for hybrid programming, and user-customized models, namely, a coal powder particles interaction model (a particle construction form, a particle mass change model, a particle size dynamic change model and a volatile element precipitation model) and a mass change storage mechanism, are coupled, so that numerical simulation of interaction of the coal powder particles in burning is realized. Experiments show that change rules of coal powder particle temperature and so on obtained through the numerical simulation method are generally consistent with experiment data. Through adoption of the method, a real, objective interaction mechanism of coal powder particles in burning is disclosed conveniently and efficiently, thereby providing powerful theoretical basis and technological support for improvement and optimization design of the coal powder burning technology.