本文从公司外部环境视角，在委托代理理论、竞争理论和公司治理理论的基础上，选取中国2016~2019年沪深两市A股上市公司为研究样本，研究市场竞争程度和公司治理各个因素对盈余管理的影响以及公司治理在其中发挥的作用。基于实证分析，本文验证了激烈的产品市场竞争会导致掠夺风险效应从而引发盈余管理，且两者呈正相关；有效的公司治理行为能够减少企业盈余管理行为；同时，提升公司治理水平也将使得产品市场竞争和盈余管理程度的负相关关系显著减弱。这对我们理解企业外部环境变化对企业行为的影响、改善公司治理机制对盈余管理行为的重要意义有着积极作用。

This paper, from the perspective of corporate external environment, on the basis of principal-agent theory, competition theory and corporate governance theory, selects China's Shanghai and Shenzhen A-share listed companies from 2016 to 2019 as research samples, and explores the influence of various factors of corporate governance on the relationship between product market competition and earnings management. Based on the empirical analysis, this paper verifies that the intense product market competition will lead to the looting risk effect, which leads to earnings management, and the two evidences are positively related. Improving the corporate governance structure can effectively restrain the earnings management behavior of enterprises. At the same time, the corporate governance level will also effectively restrain the degree of earnings management induced by product market competition. This plays an important role in our understanding of the effects of corporate external environment changes on corporate behavior and improving corporate governance mechanism on the behavior of earnings management.