从国内外江、河、海底隧道的建设经验出发，根据长隧道及高速铁路隧道的设计、施工经验，论述了台湾海峡海底隧道采用铁路隧道方案的合理性；给出了台湾海峡海底隧道的断面形式、断面面积及洞门形式建议方案；提出了台湾海峡海底隧道选择施工方案要点；介绍了国内江河海底隧道的建设情况；重申审核工程修建好坏的理念，及修建过江、过海隧道比桥梁的优点；最后给出了修建海底水下隧道急需深入研究和解决的重大关键技术问题。

Based on the design and construction experience of rivercrossing tunnels, subsea tunnels, long tunnels and highspeed railway tunnels, the author concludes that the reasonable option for Taiwan Strait subsea tunnel is railway tunnel. The crosssection types and areas, portal types and construction schemes of Taiwan Strait subsea tunnel are recommended in the paper. The author presents the situation of construction of rivercrossing tunnels and subsea tunnels in China. Moreover, the author provides some new concepts, including the idea that rivercrossing tunnels and subsea tunnels have more advantages than bridges. At last, the author presents the key technical problems that need further researches in the construction of subsea tunnel.