The invention discloses a wind power generation primary frequency modulation function realization method based on wind farm power control. The method comprises the steps that in an active power control device of a wind farm of grid-connected operation concentrated access, the sag frequency adjustment control policy of the wind farm power is added; the frequency f of the wind farm of grid-connected operation concentrated access is monitored in real time; when the power grid frequency f exceeds a set primary frequency modulation dead zone, the power given target value P1 of the wind farm after primary frequency modulation is calculated according to the control policy; the active power control device reassigns the new power given target value P1 to each wind turbine; and each wind turbine adjusts the respective output according to an instruction to realize the primary frequency modulation function of the whole wind farm. According to the invention, a single wind turbine in the wind farm does not need to have the primary frequency modulation ability; and directly through the means of wind farm power control, the whole wind farm has the primary frequency modulation effect similar to the effect produced by a synchronous generator which relies on a governor.