Analytical knowledge of auditors is considered as one of the most important examples of the auditing profession, which makes it possible to strengthen professional judgments. Analytical knowledge is actually specific patterns of the thinking styles of auditors who try to apply a more comprehensive review with the ability to face the situations and functions of different clients. The purpose of this study is investigating the effect of the auditor's analytical thinking on improving the auditing quality. This study is considered to be a developmental, exploratory and hybrid methodology in which the interview tool was used for the qualitative part, relying on the implementation process of the ground theory, and in the quantitative part, the research hypothesis was tested with the questionnaire tool and using structural equations. In this study, in the qualitative part, 12 academic experts were present to participate in the data theory analysis of the foundation, and in the quantitative part, 402 auditors working in the audit organization and private sector audit institutions participated. The results of the study in the qualitative part of the total of 261 open codes indicate the existence of 3 categories, 6 components and 33 conceptual themes in the form of a hexagonal model. The result in the quantitative part also showed that the auditor's analytical thinking has a positive and significant effect on audit quality.