Sinahahnia fanjingshan is known only from its type locality in Guizhou, China. The genus description notes a yellowish-brown carapace and five pale chevrons on the back of the abdomen.
In S. fanjingshan, the male’s patellar apophysis on the palp ends in two branches, and the female’s spermathecae are peanut-shaped.
The paper records specimens from Fanjingshan Nature Reserve in Guizhou near Maxi’ao Tunnel (1,239 m), Mianxuling (1,974 m), and Jinding (2,214 m).
An extinction-risk assessment has not been added yet.