The invention relates to a rapid frequency control method and system for a new energy station. The rapid frequency control method comprises the following steps that when a grid frequency f obtained bysampling at the grid-connection point of the new energy station is monitored to exceed a dead zone range, controlling a grid frequency sampling and monitoring device to enter a fast frequency sampling period working mode, locking an active instruction P0 of a power station AGC before the frequency enters a dead zone, and acquiring a real-time grid frequency f and a real-time active instruction P1of the power station AGC; and then calculating and generating a fast frequency control active power instruction according to the value of the grid frequency f, the real-time active instruction P1 ofthe power station AGC and the size of the active instruction P0 of the power station AGC before entering the dead zone so as to carry out power control on a new energy unit. The method is fast in response speed and meets technical requirements. In addition, the method and the system provided by the invention are friendly to build new energy power stations, can realize fast frequency control of thenew energy power stations through transformation in a small range, and are small in hardware transformation difficulty and free of constraint by factors such as the type of the new energy power station, geographical environment and communication mode/protocols, and good in operability.