Based on modeling of photovoltaic cell and array according to project requirement and modeling of converter according to grid-connected control tragedy, the model of photovoltaic generation system is established. By principle of constant power-loss, the equivalent method of large photovoltaic station is proposed in order to being applied in large power system simulation. Thereafter, making use of the new acquired model, the analysis of security and stability of 2011 Haixi Grid integrating large-scale photovoltaic station is constructed, including security characteristic, steady state stability limit and transient stability limit in power delivery and receive mode, so as to guide the operation controlling and planning in Haixi Grid.