Abstract: According to the nonlinear multi-peak P-V output characteristics of PV arrays under partial shading conditions,a maximum power point tracking（MPPT）control algorithm based on modified gray wolf optimization algorithm is proposed. The proposed algorithm replaces the linear convergence factor in the traditional gray wolf optimization algorithm with a nonlinear convergence factor,which improves its dynamic performance. Experimental results show that the proposed MPPT algorithm can effectively track the maximum power point of the photovoltaic array under partial shading conditions. It not only has a faster tracking speed,but also has a tracking accuracy of 99.1%.