The shareholding structure of multiple large shareholders (hereafter MLS) is widespread in China. This paper focuses on MLS and takes China's A-share listed firms from 2008 to 2020 as samples. It finds that compared with one large shareholder, MLS will reduce the level of corporate tax avoidance. The mediation effect model shows that MLS play a supervisory role on the tunneling, thus reducing tax avoidance activities of controlling shareholders to cover up the tunneling.