The principle of field synergy is to simulate the comfortableness of room in this study. The parameters U, V, W and input position of wind are calculated to simulate comfortableness of room. Temperature and velocity fields are simulated by COMSOL Multiphysics software. Comfortable degree is calculated by field synergy mean square root method in this research. The simulation result shows that field synergy angle decreases while comfortable degree increases. It is very obvious that the right input position of wind leads lower field synergy angle.