Abstract: In order to solve the problem that the pressure fluctuation of condensing jellyfish tube in the process of primary frequency modulation of coal-fired generator set affects the frequency modulation capability, the research on the pressure curve correction control of condensing jellyfish tube based on primary frequency modulation capability was carried out. By introducing the main steam pressure correction and the new slip pressure curve based on the primary frequency modulation capability, the fine adjustment of the main steam pressure is realized, and the frequency modulation response speed and accuracy of the unit are improved. At the same time, the AGC reverse locking mechanism is designed to avoid the reverse adjustment of AGC when the system frequency oscillates and ensure the correctness of the frequency modulation direction. By modifying the control strategy of pressure curve, the pressure setting value of condensate tube is dynamically adjusted to optimize the operation of condensate water system. In the example application, a coal-fired generator set was selected to optimize the pressure control curve of condensate tube, and the effect before and after the depth conversion of condensate pump was compared. The results showed that the frequency modulation ability was significantly improved, and the pressure fluctuation was significantly reduced, which verified the effectiveness and practicability of the proposed control strategy.