Based on the quadratic interpolation method， a power control strategy of photovoltaic（PV） generation system is proposed. With this control strategy， the PV system can operate on the power limitation mode to flexibly adjust the power output， and automatically switch to the maximum power point tracking（MPPT） mode when the maximal power output is still less than the demand. Based on the principle of quadratic interpolation method， data updating algorithm of sampling points， solution when the calculated reference voltage is out of limit and the way to achieve the fault ride-through（FRT） capability are discussed. Simulation results verify the correctness and feasibility of the proposed control strategy.