To investigate the mechanism of heat transfer process between the pilot phase of air and sand body at the experimentalSstage in indoor sand-therapy room. Using the method of CFD to build the three dimensional thermal-physical model and mathematical model of indoor sand-therapy room at the experimentalSstage,the fluid-solid coupling heat transfer problem was resolved In the FLUENT. Temperature field between the pilot phase of air and sand body was numerically simulated and experimentally verificated. The result of temperature field in the pilot phase of air and sand body was calculated and the data of numerical simulation was matched to the experimental date. In contrast with the Turpan sand therapy field, suitable for indoor the temperature steady layer and the depth of sand-therapy was obtained by simulating. Through pressing a single-sided natural ventilation, indoor sand-therapy room environment has a certain degree of thermal comfort. Indoor sand therapy room can provide appropriate therapy temperature and relatively comfortable thermal environment,and provide theoretical basis and practical guidance for the further improvement of the indoor sand-therapy system design.