Dai Zhuang or Thu Lao is a Tai language spoken in Yunnan, China and northern Vietnam.

In Vietnam, Thu Lao (autonym: La Hừ, meaning 'black earth') is spoken in the following 7 villages (Nguyễn 2014:14).

[2] Jerold Edmondson describes Thu Lao as a Central Tai language with about 200 speakers that retains voiced initial consonants in low tones, like Tay of Trùng Khánh District, Cao Bằng Province.

The Baiyi are classified as ethnic Dai in Hekou, and as Zhuang in Wenshan and Maguan.

Many Dai Zhuang dialects preserve voiced stops inherited from Proto-Tai (L-Thongkum 1997).