Using a sample of all A-share listed companies in Shanghai and Shenzhen Stock Exchanges from 2004 to 2016， this paper studies the relationship between the second type of agency costs and voluntary disclosure of earnings pre-announcement. On this basis，it further examines the effect of violation penalties of securities regulatory agencies on the relationship between them.The findings show that the higher the second type of agency costs，the lower the probability of voluntarily disclosure of earnings pre-announcement. The securities supervision has a significant positive effect on voluntary disclosure of earnings pre-announcement，and can also weaken the negative correlation between the second type of agency costs and the voluntary disclosure of earnings pre-announcement to a certain extent. This paper explains the voluntary disclosure behavior of listed companies from the perspective of agency conflicts between controlling shareholders and minority shareholders，and provides empirical evidence for testing the governance effect of securities supervision.