The invention discloses a control system and a control method for regulating a rotation speed of an electrically driven feed pump of a nuclear power station. The control system comprises a digital control system, a scoop executing mechanism, a hydraulic couple and a water feed pump that are connected in sequence, wherein the digital control system comprises a rotation speed signal acquiring unit and a central processing unit; the rotation speed signal acquiring unit is used for acquiring a rotation speed set value signal and a rotation speed feedback signal; the central processing unit is further used for obtaining a scoop opening degree signal according to logic processions upon the rotation speed set value signal and the rotation speed feedback signal, so that the scoop executing mechanism can regulate a fuel level of the hydraulic coupler according to the scoop opening degree signal so as to control the rotation speed of the water feed pump. According to the control system and the control method for regulating the rotation speed of the electrically driven feed pump of the nuclear power station disclosed by the invention, the digital control system is applied to performing logic processions about control of the rotation speed, so that a PLC independent from a DCS in the prior art is omitted; meanwhile, the number of apparatuses of the control system and signal switching between the DCS and the PLC are reduced, a response time of the system is effectively shortened, the efficiency and the stability of rotation speed regulation are increased.