Combined with the characteristics of distribution network, this paper introduces the life cycle cost theory, from three aspects of economic benefits, social benefits and environmental benefits to construct the evaluation system of comprehensive benefits of distribution network planning. In view of the benefit evaluation of distribution network in the presence of uncertainty, it establishes a comprehensive benefit evaluation model of distribution network planning based on the cloud matter-element theory, which combines with advantages of cloud model reasoning under uncertainty and qualitative and quantitative analysis of matter element theory, and takes full account of the fuzziness and randomness of distribution network benefit level boundary information. Finally, a numerical example is analyzed to verify the scientificity and validity of the model. This work is supported by National Natural Science Foundation of China (No. 51307060 and No. 51607068) and Natural Science Foundation of Beijing (No. 3164051).