The invention discloses a control structure used for coordinating different fans in a wind power farm for achieving the low voltage ride through capacity of the wind power farm. The control structure comprises an operation management layer, a wind power farm control layer and a wind generation set control layer. According to the control structure, the requirement that the wind power farm supplies certain reactive voltage support to a power grid can be met during network voltage drop, the low voltage ride through capacity of the wind power farm can be well improved, moreover, the capacity of dynamic reactive power compensation equipment can be saved, and good economical efficient can be achieved in practical engineering application.