The invention discloses a photovoltaic power generation maximum power tracking method capable of correcting open-circuit voltage online in order to solve the problem that when outside environment temperature greatly changes, a photovoltaic array cannot quickly track the maximum power point. The method is characterized by including the steps of building a model of a given temperature and an irradiance photovoltaic cell, building a model of different temperatures and the irradiance photovoltaic cell, improving the maximum power tracking control strategy of the open-circuit voltage, a grid-connected inverter control strategy and other contents, and building a photovoltaic power generation system including a photovoltaic cell model, a boost chopper circuit and a grid-connected inverter through PSCAD/EMTDC simulation software; the open-circuit voltage is updated according to outside environment changes, so that the photovoltaic system is stabilized at the maximum power point quickly; the incremental conductance method is introduced to improve the steady-state performance at the maximum power point so as to further improve energy conversion efficiency of the photovoltaic power generation system; an effective means is provided for improving the maximum power point tracking efficiency of the photovoltaic array and reducing energy loss of the photovoltaic array.