Abstract: Ubiquitin and small ubiquitin-like modifier (SUMO) can be covalently attached to specific protein substrates, undergo ubiquitination modification and SUMOylation modification, and affecting their stability, activity, localization or interaction, thus regulating various cell activities, including DNA damage repair, cell cycle, apoptosis and immune responses. When cells experience DNA damage, ubiquitination modification and SUMOylation modification regulate the function and interaction of relevant proteins, thereby participating in the process of DNA damage repair and signal transduction. These modifications are indispensable for maintaining genome integrity. Recent studies have revealed that ubiquitination modification and SUMOylation modification in these repairs. The author reviews these roles, so as to provide a reference for in-depth understanding of the ionizing radiation-induced DNA damage repair mechanism.