根据企业会计准则及相关规定，企业应当在报表中披露相关客户信息。由于大客户会影响到企业的正常经营，可能会严重影响到企业盈余管理行为，本文以2018-2021年信息传输、软件和信息技术服务业的数据为样本，探讨客户集中度与盈余管理的关系，并深入探讨审计质量作为外部监管的重要衡量指标，是否能抑制客户集中度对盈余管理的影响。通过回归分析发现：客户集中度越高，盈余管理行为越多；审计的质量越高，盈余管理行为越少；审计质量在客户集中度与盈余管理之间存在着调节作用。

According to the Accounting Standards for Business Enterprises and relevant regulations, enterprises should disclose relevant customer information in their financial statements. Because key customers will have an important impact on the business activities of enterprises, which will affect the earnings management of enterprises, this paper takes the data of information transmission, software and information technology services industry from 2018 to 2021 as a sample to explore the relationship between customer concentration ratio and earnings management, and further explore whether audit quality, as an important measure of external supervision, can inhibit the impact of customer concentration ratio on earnings management. Through regression analysis, it is found that there is a significant positive correlation between customer concentration ratio and earnings management; There is a significant negative correlation between audit quality and earnings management. Audit quality can inhibit the impact of customer concentration ratio on earnings management.