Several numerical infection simulations have been performed to identify the transmission route of influenza virus. In this case, the most important issue is shortening the calculation time. Thus, according to different calculation condition, whole recalculation is not required. Then, only the necessary parts of the numerical model can be used for calculation by calculating for multiple numerical models separately and applying the results to the calculation of other models.That leads to a shortening of overall calculation time. In this study, as the first step, to construct a coupled calculation method, the calculation for a room model was performed using the calculation results of a respiratory organ model. Then, the result obtained by the calculation for the respiratory organ model was coupled on the respiration flow of a human model in the room model. That showed the possibility that the method could be applied to coupled calculation for multiple numerical models and contribute to shortening of calculation time.