Fan control method and system

A fan control method for a fan control system, used to control a fan control module and a fan. The fan control method includes: controlling corresponding relationship between the fan control module and the fan; controlling switch-on time and switch-off time of the fan; selecting control mode that includes at least one of the temperature mode, quantity mode and tracking mode; switching on the fan; detecting parameter that includes at least one of the surrounding temperature, quantity of the heat source and moving track; adjusting at least one of the flow volume and flow direction based on the parameters, wherein the temperature mode is to adjust the flow volume and flow direction according to the surrounding temperature, the quantity mode is to adjust the flow volume and flow direction according to the quantity of the heat source, and the tracking mode is to adjust the flow volume and flow direction according to the moving track of the object.