To address the flexible and economical peak shaving issue of power grid in the presence of large-scale renewable energy penetration, a multi-source complementary peak shaving scheduling method with detailed consideration of nuclear power risk quantification is proposed. Firstly, the mechanism of low load peak shaving for nuclear power is analyzed, and its peak shaving risk quantitative indicators are considered to balance its economical efficiency and safety. Secondly, a wind-solar-thermal-nuclear-storage based multi source complementary peak shaving scheduling model is established, which takes the minimum total operating cost as the optimization goal, and considers the loss of wind and solar power waste and the increased power generation cost of different power sources participating in peak shaving, and the mode is solved. Finally, case study demonstrates the effectiveness of the proposed optimization scheduling model and its superiority. The results show the proposed method can achieve a 94.17% reduction in wind and solar waste compared to thermal power peak shaving and nuclear power peak shaving without energy storage participation, and a 1.26% reduction in carbon emissions. This indicates a significant improvement of the peak shaving ability of a high proportion of wind and solar power grid within multi source complementary mode. The proposed method provides a practical approach to realize economical and low carbon economy operation of multi source complementary system.