With a goal of carbon peaking and carbon neutrality, the power industry is facing huge pressure of low carbon transformation. Actively planning is needed for the orderly withdrawal of coal power and accelerating the replacement of clean power sources while ensuring grid security. This paper establishes a two-layer iterative optimization model for the synergistic evolution of coal and clean power sources. The upper layer is a power source investment decision model that takes into account the fluctuating characteristics of load and wind-PV output, and makes decisions using the month as the time unit. The lower layer is a short-term operation optimization model that aims at operating economy and meeting peak regulation capacity. The impact of economic, technical, safety and environmental factors on the evolution path is analyzed, and a comprehensive evaluation index system is constructed to identify the weak links of the path. Finally, the proposed model is used to study the synergistic evolution path of coal power and clean power sources in a provincial power system over the next 30 years. A comprehensive evaluation of the evolution path is carried out, and targeted energy development suggestions are made for the weak links. This work is supported by the Natural Science Foundation of Shandong Province (No. ZR2019MEE078).