The invention discloses a gene methylation detection method. The method comprises the steps of: subjecting a to-be-detected DNA sample, a negative control, a positive control and a no template control to PCR amplification reaction, with the DNA sample in the PCR amplification reaction being bisulfite modified DNA, carrying out duplex PCR amplification reaction on a detection gene and a reference gene, and interpreting a parameter range to judge the methylation condition of the detection gene of the to-be-detected DNA sample. By the mode, the gene methylation detection method provided by the invention has the advantages of strong specificity, duplex reaction, high sensitivity, small pollution, simple and quick operation, and safety, etc., and the detection result has good accuracy and repeatability. Thus, the method has certain auxiliary diagnosis effect on early detection of colorectal cancer and other cancers.