With the continuous advancement of financial globalization, the volatility of REITs(real estate trust and investment funds) market price has intensified, and the risks spread among different REITs markets has accelerated. It is necessary to accurately measure the risks brought by price fluctuations and their spillover transmission mechanisms. From the perspective of multi-market correlation, this paper studies the extreme risk spillover effects via combining Vine Copula model and CoVaR(contingent value at risk) model. The main conclusions are as follows: The interdependence among international REITs markets has obvious regional agglomeration characteristics; the average tail interdependence outward in European and American markets is higher, but the tail interdependence among Asian REITs markets is weaker; most of the major REITs markets have a two-way risk spillover effects and show asymmetry; the two-way risk spillover effects among REITs markets with strong interdependence structures are extremely obvious. This study is helpful to globally grasp the extreme risk spillover effects of REITs markets, to provide reference for maintaining financial stability and preventing risk transmission among markets in different regions, and to help investors manage risks.