Abstract: In order to meet the low voltage ride-through capability of photovoltaic power plants, it is necessary to ensure that photovoltaic power plants can still maintain grid connection when grid voltage drops, and provide certain active and reactive power to the grid quickly. A multi-vector model predictive power control method is proposed, which avoids the repetitive modulation of six pairs of basic voltage vectors, and selects a pair of basic voltage vectors and two zero vectors to perform the modulation symmetrically in each cycle. The grid side current harmonic content is reduced effectively. The calculation time is also reduced, and the grid side current has a fixed switching frequency. In addition, in order to avoid the observation error caused by the low voltage ride through of the observer responsible for the feedback signal and save the hardware cost, the sliding mode observer is introduced here. The filtering method is improved to avoid dependence on accurate angular frequency. Finally, the correctness and effectiveness of the proposed method are verified by simulation and experiment.