After the male ligation semen like water, considering that may be too frequent sex, or prostatitis, seminal vesiculitis, under normal circumstances, after the ligation surgery ejaculation semen will not become thin, just does not contain sperm. If a man has frequent sex after ligation, it will affect the consistency of the semen, and it is recommended that the patient have sex once a week, take more rest, and avoid exertion. If there is prostatitis, seminal vesiculitis and other diseases, may also cause the semen thin like water, it is recommended that the patient to go to the regular hospital examination, follow the doctor’s advice to take azithromycin, cefixime and other drugs treatment. After the male vasectomy, the pathway of testicular delivery of spermatozoa is interrupted, and the ejaculated semen mainly contains the components of seminal plasma, but no spermatozoa. Seminal plasma mainly consists of a large amount of water, inorganic salts, sugars and other active substances, which are secreted by the prostate gland seminal vesicle glands and urethral bulbous glands together. It is a safe, effective and convenient form of contraception. Thin semen after male ligation may also be caused by other factors, and patients are advised to go to regular hospitals for timely consultation and treatment.