Biopolymer soil method has been considered the latest technological innovation in the field of soil improvement purposes. Biopolymers such as agar, xanthan, casein and so on have been commonly studied to improve strength, reduce the hydraulic conductivity and dust control of soils. In this study, the effect of gellan gum biopolymer on strengthening bentonite slurry was studied. In order to observe the effect of gellan gum on the bentonite strengthening effectiveness, the unconfined compression tests were conducted on gellan gum-modified bentonite with consideration of gellan gum concentration, thermal curing process. The experimental results were combined with studies conducted by Tran and Takeshi (2021) to extend the understanding of the strength properties of gellan gum-treated bentonite. Furthermore, the effect of gellan fum-bentonite slurry for emergent excavation stabilization was evaluated via 2D finite-difference program (FLAC2D), considering gellan gum concentration and thickness of the treatment area. The numerical results support the application of gellan gum biopolymer to excavation wall stabilization.