中文摘要：

本文通过建立股东、管理层和审计师三方参与的两委托人一单代理人博弈模型，研究了固定审计费用下不同审计师变更方式对审计质量的影响。研究结果表明，审计师强制性单期变更与审计师强制性定期变更下，审计师与管理层之间的合谋将导致严重的财务舞弊；而在审计师自愿性变更下，股东可以利用解聘现任审计师这一威胁来阻止审计师和管理层之间的合谋，使得审计师和管理层的最优策略均为真实披露公司的盈余信息，并发表标准无保留审计意见。

英文摘要：

In this paper, we build a two principals-one agent game model involving shareholders, management and auditors to study how different auditor rotation mechanisms affect audit quality under fixed audit fee assumption. The results show that under mandatory rotation in a single period or in fixed periods, the conspiracy between auditors and management will lead to serious financial fraud. However, under voluntary auditor rotation, shareholders can stop the conspiracy between auditors and management by threatening dismissing the current auditor, reaching the equilibrium where the optimal strategies for both auditors and management are disclosing the true earnings with a standard unqualified audit opinion.