Small penis syndrome is a disease caused by congenital or acquired factors. In clinical practice, a considerable number of men are dissatisfied with their penis size, leading to a persistent need to increase penis size. However, existing therapies (including psychological interventions, medication, and surgical procedures) have limited efficacy and often come with significant side effects. The vacuum erection device, as a non-invasive treatment method, has a positive effect on preventing penile shortening after radical prostatectomy for prostate cancer and penile elongation in rats during puberty and adulthood. The purpose of this article is to systematically explain the impact of vacuum erection device on penis size, in order to provide references for clinical practice.