This paper selected three clean energy news reports from China Daily to analyze the logico-semantic relations and function of the clause complex in the discourse based on Halliday’s Systemic Functional Grammar. The study aims to explore the characteristics of logico-semantic relations in the scientific news report, so as to have a deeper understanding of the sentence structure in the text. According to the five categories of logico-semantic relations, the study found that there are 64 clause complexes, with 22 locution projection, 13 enhancement relation, 12 elaboration relation, 9 idea projection and 8 extension relation. Projection clause type is generally used to evaluate the progress and effect of energy development projects; extension clause type usually emphasizes the impact of energy development or energy projects; enhancement clause type indicates when, where and why the energy transition and energy development projects are taking place and elaboration clause type is used to provide additional instruction of the project. In addition, this study also provides a reference for English learners and news writers.