"Tiny Cooling Fan" designed to MCS51 microcontroller core, the ambient temperature by a temperature sensor for data collection in order to establish a control system that allows fans with changes in temperature and automatically change gears, to achieve "high temperature, wind, temperature low, wind weak "performance. In addition, "Tiny Cooling Fan" via the keyboard when the temperature is higher than the control panel, the user can set the minimum fan operating temperature within a certain range, when the temperature is below the set temperature, "Tiny Cooling Fan" will automatically shut down, Fans in turn restart.