The forms of insider trading in China’s capital market are various and covert, among which, it is one of the common means for the major shareholders selling of original non tradable shares by using the opportunity of earnings forecasts. In this paper, we take the major shareholders selling events near the disclosure of earnings forecasts of listed companies as the research object. The results show that, compared with the mandatory earnings forecasts, voluntary earnings forecasts is more likely to become a channel for the major shareholders to make use of information advantages to sell their holdings at the right time, and accounting conservatism can significantly negatively affect the insider trading behavior of the major shareholders. This article further divides earnings forecasts news into good news and bad news, and finds that, before the disclosure of earnings forecasts, the worse the bad news, the more the big shareholders reduce their non tradable shares; or after the disclosure of earnings forecasts, the better the good news, the more the big shareholders reduce their non tradable shares. It can be seen that more robust financial information can restrain insider trading in concealing bad news, but can aggravate insider trading in hiding good news.