Based on the pressure theory and institutional theory, this paper explores the impact of CICPA's superimposed regulatory pressure of interview system and practice quality inspection system on the audit quality. Taking the A-share non-financial listed companies from 2014 to 2018 as the objects, the study finds that under the superimposed regulatory pressure of CICPA, auditors significantly improve the audit quality. It is further found that the effect of superimposed regulatory pressure on the improvement of audit quality is only obvious in face-to-face interviews, auditors with same sex, auditors with long practicing years, and auditors with numbers of customers. It is also founded that there is a substitution between superimposed regulatory pressure and legal regulatory pressure. And in the face of the superimposed regulatory pressure, they also charge extra premium compensation. The conclusions can clarify auditors' behaviors with the pressure of overlapping supervision, and have significance on the self-discipline supervision of the securities audit market.