The invention belongs to the technical field of lung adenocarcinoma prediction, and specifically relates to an identification of early diagnosis markers of lung adenocarcinoma based on co-expression similarity, and a constructing method of a risk prediction model. The constructing method includes the steps of: data remodeling and grouping, data standardization, phase specific gene extraction, geneco-expression correlation analysis, unsupervised cluster analysis, specific and non-specific co-expression network analysis, functional pathway gathering, significant variation pathway identification, screening of early screening marker genes by using an REE algorithm, establishment of a classification model based on early screening risk genes, survival analysis verification, and the like. The identification of early diagnosis markers of lung adenocarcinoma based on co-expression similarity, and the constructing method of a risk prediction model can realize the early diagnosis of lung cancer,and can identify gene markers which change significantly with the progress of lung cancer at the same time.