Growing cutting-edge study has demonstrated the RNA m6A methylation's critical role in regulating tumorigenesis and progression all over the world, while it is still a mystery whether RNA m6A methylation has a positive impact on breast cancer treatment. In this article, we utilize bioinformatics to analyze three data sets including TCGA-BRCA, GSE96058, and GSE25066 and discover that breast cancer samples could be divided into 4 subtypes, which are quiescent, m6A methylation, protein-binding, and mixed, clarified by the expression level of m6A-related genes. R-survival analysis results also prove that the survival rate of breast cancer samples of the four subtypes significantly varies and remarkable differences in the number of exons' skip among the four subtypes can be seen according to the analysis of breast cancer gene expression characteristics. The degree of TP53 mutation and copy number loss is most obvious in the protein-binding subtype when it comes to tumor driver genes. Among the DNA damage repair genes, there is a sharp increase in the copy number of RAD54B of the protein-binding subtype, but fewer mutations in other DNA damage repair-related genes and copy number deletion is everywhere. Results of m6A methylation influencing on the proportion of infiltrated immune cells also indicate significant differences of the four m6A subgroups in macrophages M0 and mast cells resting which are closely correlated to patient prognosis. In addition, findings of the highest tumor stemness index and the lowest in the m6A methylated type in breast cancer samples can prove the critical role of the high expression of m6A reader protein in the progression of breast cancer.