A study was design a small mushroom box, it not only crop, it also can decoration and embellish. Using CFD to investigate temperature and humidity in the mushroom box to make a best condition for mushroom grow. Include investigate a coefficient of porous and its adjustment method. Adjustment this coefficient to make proportionate airflow. It will easier to let temperature and humidity be even. Before design, using simple material to building, consider real condition to simulation, investigate porosity distribution to effect airflow, atomized water diameter scale and flux of water to effect temperature and humidity.