Information mining by analyst tracking and short selling are important channels for investors to obtain corporate information. In the case of analysts with optimistic bias，short-selling investors focusing on negative information mining functions can make up for the lack of analyst bias，which is of great significance for improving the quality of corporate information disclosure. Based on the exogenous events of the pilot short selling implemented in 2010 in China， this paper uses DID method to empirically study the relationship between the negative information mining function of the short selling and the analyst tracking in the case of the deviation of enterprise information，and the impact on the quality of corporate information disclosure. The study finds that short selling mechanism can promote negative information disclosure，correct the impact of analyst bias，make up for the shortcomings of analyst tracking， and improve the quality of corporate information disclosure when analyst optimistic bias exists. However，when the analyst has no optimistic bias，short selling mechanism can not improve the quality of information disclosure.