The application discloses a power-friendly primary frequency modulation control method and system of a receiving-end grid. According to the method and system, under the circumstances that the grid frequency of the receiving-end grid exceeds a primary frequency modulation dead zone range set by a grid-connected set, the actual power of the grid-connected set is in an adjustable range, and the grid-connected set has the excess power compensation capability, an excess compensation coefficient of the grid-connected set is calculated according to a main steam pressure offset; and with the excess compensation coefficient, dynamic correction is carried out on a current slip of the grid-connected set and a corrected slip is obtained in real time, so that primary-frequency-modulation excess power compensation adjustment is carried out on the grid power gap. According to the application, on the premise that the safe and stable operation of the set is not affected, the grid power gap is compensated by using the thermal storage of the set fully, the frequency modulation potential of the set is fully realized, and the energy source is utilized fully. Moreover, excessive energy in the set is released and thus the main steam pressure becomes stable, so that the set works stably.