Fan speed control method

The invention discloses a fan rotating speed control method which is applied to a server with a fan controller. When the server is started at the moment, the fan controller acquires a maximum rotating speed value of a configured fan according to a feedback signal, judges the currently-used fan type, and correspondingly selects a first type of fan rotating speed meter or second type of fan rotating speed meter corresponding to the fan type to drive the currently-used fan to operate. The performance of a second type of fan does not need to be corrected according to a first type of fan, and further a design progress of the server is not influenced.