Ovarian cancer is one of the most dangerous and predominant gynecological cancers, with a high cancer-related mortality rate in women. However, current testing methods are still limited, and if detected early, patients have a five-year survival rate of 92%. Therefore, early diagnosis and detection are crucial for diagnosing and treating ovarian cancer. According to the results of the researchers' previous research, it has been found that CDO1 and HOXA9 genes are hypermethylated in ovarian cancer, and the expression of free DNA methylation in plasma can be used as one of the biomarkers for detection. In a single-center retrospective/prospective study, it has been demonstrated that the detection of CDO1 and HOXA9 methylation levels based on cell-free DNA in blood and comparison with ovarian pathology results can achieve \>80% sensitivity and specificity. To further explore the application of methylation detection technology in ovarian cancer, the application value of non-invasive diagnosis and prognosis follow-up will be explored to clarify the clinical application value of DNA methylation for early detection of ovarian cancer in the real world. The investigators will conduct a prospective multi-center cohort study, referred to as the OVAMethy study, which will involve more than ten research centers and is expected to recruit more than 5,000 clinical subjects to test the methylation detection kit and histopathology further, ROMA index and imaging results, and sensitivity and specificity technical performance parameters.