Abstract: Taking private listed companies in China from 2009 to 2015 as examples, this paper investigates the influence of the informal system of the reputation of independent directors with accounting professional background and social trust on the quality of internal control. The research finds that the reputation of independent directors with accounting professional background and the level of social trust have a significant positive impact on the quality of internal control of enterprises, and as the director of the audit committee, the accounting professional independent director with high reputation has more obvious influence on the quality of internal control. With the improvement of social trust, the positive impact of the reputation of independent directors with accounting professional background on internal control has been strengthened.