Qiongzhou Strait Crossing Project is an integral part of GuangdongHainan railway. On basis of analysis on the documents related to the natural conditions of Qiongzhou strait and investigations on the largediameter shieldbored underwater tunnels built in China and foreign countries, the author believes that it is suitable to build  Qiongzhou Strait Crossing Railway Tunnel by means of shield boring method. Then, the author makes some preliminary proposals for Qiongzhou Strait Crossing Railway Tunnel and NanningQinzhouYangpu railway. The paper can provide reference for the construction of Qiongzhou Strait Crossing Project in the future.