With the progress of information technology, although the Chinese government has constantly improved the tax collection and management mode, corporate tax avoidance still widely exists. The tax avoidance behavior of enterprises increases the uncertainty of tax payable and after-tax cash flow of enterprises to some extent, thus increasing the uncertainty of investors' expected return rate. Therefore, the tax avoidance behavior of enterprises affects the financing cost of enterprises to some extent. However, there are few studies on the impact of corporate tax avoidance on the cost of equity capital, and most scholars study all listed companies. Based on this, this article on China's real estate enterprises as the research object, with China's 90 listed real estate companies in 2009-2018 data as sample, respectively, based on book-tax differences (BTD) and the effective tax rate (ETR) the Angle of two kinds of real estate enterprises tax avoidance measure, USES empirical approach to analyze corporate tax avoidance impact on equity capital cost. The results show that the equity capital cost of real estate enterprises decreases first and then increases with the increase of tax avoidance.