New challenges are presented to power system with significant wind power penetration. In some regions of China， due to inadequate power system peaking capacity and local loads， a lot of wind power is wasted during valley load periods. To optimize the use of wind energy resources， a generation maintenance scheduling model with significant wind power penetration is presented， considering the different output characteristics of wind power in different seasons and different types of units with different peak capability. The waste wind during valley load periods is reduced and the energy efficiency is improved by reserving reasonable peaking capacity when maintenance is scheduled. An effective modeling method is designed， transforming the probability integration objective function into mixed-integer programming problem byδ method. The analysis and discussions on the results of numerical examples verify the feasibility and effectiveness of the model and method.