To establish the three-dimensional model of dormitories in higher institutions, the CFD software is employed to simulate numerically the indoor airflow distribution conducted so that the wind speed and temperature surrounding the human body as well as the PMV-PPD and Mean age of air distribution of the cross section around the human’s head and sciatic nerves can be measured. Specifically, the above-mentioned two indexes PMV-PPD and Mean age of air are supposed to be used in the analysis of the differences caused by the varied positions of two air supply grilles on the human thermal comfort. The statistics collected in this analysis show that with the same wind speed, the air supply grille 2 which is farther away from the air outlet can provide better air quality and higher thermal comfort as well as relatively lower indoor temperature (lower than 1-2 °C) than the supply grille 1 does. The result obtained from this research is able to provide theatrical foundation for the air supply grille installation in dormitories of higher institutions to some extent.