To report on the diagnosis and treatment process and clinical characteristics of a child with disorder of sex development (DSD) and to conduct pathological, imaging and genetic analysis for the patient.Clinical data of the patient were collected. Genetic testing including chromosomal karyotyping, fluorescence in situ hybridization (FISH), copy number variations (CNVs) analysis, SRY gene detection and multiple ligation-dependent probe amplification (MLPA) were carried out.The patient had a social gender of male, with a history of hypospadia and breast development. Sex hormone tests showed slightly raised prolactin. Imaging results showed bilateral breast hyperplasia, abnormal seminal vesicle glands, rudimentary uterus, and underdeveloped right testis. Intraoperative examination revealed that the child had an ovary on the left and a testis on the right. The pathological results showed fibroadenomatoid changes in the breast. The patient had a karyotype of 46,XX. FISH results showed 46,XX.ish(DXZ1x2, SRYx0). Molecular testing showed that NR0B1, PHEX, CXORF21, GJB1, PQBP1, and COL4A5 genes are duplicated. There was a presence of SRY gene and absence of UYT gene.DSD should be considered in patients with genital abnormality and male breast development. Ultrasound, sex hormone test and genetic testing should be performed to confirm the diagnosis of DSD, and molecular testing should be performed if necessary. Individualized treatment of DSD patient requires cooperation of multiple clinical disciplines.