Ribosome DNA methylation marker for detection of cancer in peripheral blood and application thereof

The invention provides a ribosome DNA methylation marker for detection of cancer in peripheral blood and an application thereof. The markers comprise at least one selected from the group consisting of, by taking a human ribosomal DNA repeat fragment unit reference sequence U13369.1 as a reference, CpG sites at positions of 38974, 37148, 37013, 37082, 37076, 32936, 21740, 23407, 34657, and 28277 orthe modified CpG site. The invention also provides a system, a kit, and the like for any combination of the markers for cancer diagnosis. The methylation status of the markers is significantly different between tumor tissues and non-tumor tissues, and the markers are hypomethylated in tumor tissues, and the ROC of combination of the markers in a test set to distinguish patients with liver cancer,lung cancer, and colorectal cancer can respectively reach 96%, 94%, and 92%.