Varicocele (VC) is one of the common diseases of the male genitourinary system, and its incidence is higher in young adults. Among them, 80%-98% of VC are more likely to occur in the left spermatic vein. Previous research has found that VC could affect the temperature of the local microenvironment of the testis, oxidative stress process in the spermatogenic environment, mitochondrial function of sperm, endocrine system, and apoptosis of testes and epididymal cells. Therefore, VC will have an important impact on spermatogenic process of the testicles to cause male infertility. However, the specific molecular mechanism of VC affecting male spermatogenesis has not been fully studied. Therefore, this article will review the effect and mechanism of VC on testicular spermatogenesis.