Abstract: To avoid the blindness of power construction and to adapt the vision of large-scale renewable energy source development and to improve utilization efficiency of energy source, based on traditional power source planning model and considering multi uncertainty as well as bringing in social welfare measuring and calculation theory, a wind-photovoltaic-thermal power source optimization configuration scheme, in which the economic and welfare equilibrium was taken into account, was proposed, then a corresponding model was constructed. Taking the matching power source at the supply side for transmission channel in Tianzhong ±800 kV HVDC transmission project, which had been put into operation, for example, the proposed scheme was optimized and a corresponding optimization model was constructed. The constructed power source optimization model under the low-carbon background was applied to the outwards transmission channel of Tianzhong project to conduct the analysis on example to verify the effectiveness and practicality of the optimized model. Verification results show that the constructed planning model can effectively consider the influence of uncertain factors on the objective function, at the same time, the optimal utilization of renewable energy sources can be implemented. In the future, firstly, the macropolicy should actively promote the efficient and ordered development of clean energy and unceasingly optimize the scale and layout of new energy sources, secondly, make effort to improve social welfare brought by energy source optimal configuration and to implement the effective equilibrium of economy development and welfare in energy source field.