Abstract: In the modern world,ionizing radiation has been prevalent in daily lives and work environment due to rapid development of nuclear technology. It is invisible and exerts multiple adverse effects on various human systems and organs. As one of the cells that are highly-sensitive to ionizing radiation,male testicular germ cells are highly-susceptible to damage and exposure to varying levels of ionizing radiation can cause a range of adverse effects,including sperm parameters and sperm chromosomes and DNA,leading to a decline in male fertility and abnormal offspring development. Consequently,it is of utmost importance to promote rational and scientific protection against ionizing radiation damage while attaching importance to the life-saving cause of safeguarding male fertility,which is of great importance to the well-being of future generations. In this article,the biological effect of ionizing radiation on male reproductive organs,the damage effect of ionizing radiation on male testicular germ cells,and the protection of declined male fertility caused by ionizing radiation were illustrated,aiming to provide reference for relevant clinical trials.