聚集的规则间隔短回文重复序列（CRISPR）-CRISPR相关（Cas）系统是一种强大的基因组DNA编辑工具。基因编辑工具的增加应用，包括CRISPR-Cas系统，为生物学领域的最新进展做出了贡献，如遗传性疾病治疗、疾病相关基因筛查和检测以及癌症治疗。然而，广泛应用基因编辑工具的主要限制因素是基因编辑效率。本综述总结了影响CRISPR-Cas9系统基因编辑效率的因素的最新进展，以及CRISPR-Cas9系统优化策略。同源定向修复效率相关的信号通路和CRISPR-Cas9系统的形式和传递方法是影响基因编辑工具修复效率的主要因素。基于这些影响因素，已经开发了几种策略来提高基因编辑工具的修复效率。本综述为改善CRISPR-Cas9基因编辑系统的修复效率提供了新的见解，可能促进基因编辑工具的开发和改进。

The clustered regularly interspaced short palindromic repeat (CRISPR)- CRISPR-associated (Cas) system is a powerful genomic DNA editing tool. The increased applications of gene editing tools, including the CRISPR-Cas system, have contributed to recent advances in biological fields, such as genetic disease therapy, disease-associated gene screening and detection, and cancer therapy. However, the major limiting factor for the wide application of gene editing tools is gene editing efficiency. This review summarizes the recent advances in factors affecting the gene editing efficiency of the CRISPR-Cas9 system and the CRISPR-Cas9 system optimization strategies. The homology-directed repair efficiency-related signal pathways and the form and delivery method of the CRISPR-Cas9 system are the major factors that influence the repair efficiency of gene editing tools. Based on these influencing factors, several strategies have been developed to improve the repair efficiency of gene editing tools. This review provided novel insights for improving the repair efficiency of the CRISPR-Cas9 gene editing system, which may enable the development and improvement of gene editing tools.