The invention belongs to the technical field of power generation engineering and control thereof, and particularly relates to a system and method for controlling a high back pressure steam feed pump of a large generator set. The system comprises a high back pressure steam feed pump set, an electric feed pump set, a condenser, a low-pressure heater, a steam header, a deaerator, a condensate pump, avacuum pump, a monitoring system, a pressure measuring device, a temperature measuring device, a flow measuring device, a pipeline and a valve. According to the system and method for controlling thehigh back pressure steam feed pump of the the large generator set, the number of the equipment is reduced, the operation efficiency of the equipment is improved, and the working capacity of the exhaust steam of a steam turbine driving the steam feed pump and the condensation of the exhaust steam are fully utilized to release the latent heat of vaporization, so that the energy utilization efficiency and the flexibility of the equipment control are improved.