The invention discloses an emergency control method for suppressing disconnection of fans at sending end caused by a DC commutation failure. A DC commutation failure is taken as an emergency control starting condition, a fan terminal voltage drop control area is used as a criterion, and different low-voltage ride through active and reactive control strategies are matched according to the fan terminal voltage drop control area, so that the risk of large-scale fan disconnection at the sending end caused by disordered disconnection of a fan due to a fan low-voltage ride through failure or transient overvoltage can be effectively prevented.