Based on the "Vows" published by Huisi, the author investigated the relationship between Huisi and Guang Mountain from all aspects. Since living in Guangshan when he was 40, Huisi has propagated Buddhism Philosophy in Kaiyue Monastery, Guanyi Monastery, Qiguang Monastery and Big Su Mountain. In AD 567, Huisi left for Nanyue Mountains in Hunan Province from Guangshan at his 50s, where he promoted further development of the Tiantai Philosophy to the south area of China, as well as the formation of Tiantai Buddhism Sect. Later generations recorded the fact on the epigraph in Big Su Mountain after 17 years, which further proved that Big Su Mountain is the cradle of Tiantai Philosophy.