The potential application of tunicate cellulose nanofibers (tCNFs) as particle stabilizers for Pickering emulsions was explored. tCNFs were successfully prepared from ascidian tunic powder via mechanical ball milling with an ionic liquid as the milling medium. The morphology and structural characteristics of the tCNFs were examined by transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. Furthermore, the emulsifying properties of the tCNFs were evaluated by preparing and analyzing emulsions. The tCNFs are filamentous with a high aspect ratio and possess excellent colloidal stability, high crystallinity (76.48%), and good thermal stability (with a maximum degradation temperature of 384.20 ℃). The tCNFs are hydrophobic, making them favorable for emulsification. Investigation of the emulsifying properties of the tCNFs showed that the type of oil phase, particle concentration (c), and volume fraction of the oil phase (ϕ) can be tailored to control the characteristics of the tCNF-stabilized emulsions. Notably, the tCNFs demonstrate superior emulsifying performance when used to stabilize dodecane, achieving a minimum oil droplet size of 7.39 μm. When the particle concentration (c) exceeds 0.3wt.% or the volume fraction of the oil phase (ϕ) falls below 0.7, the emulsions display good stability and a tendency to form gellike structures. In conclusion, these findings highlight the great potential of tCNFs as effective particle stabilizers with excellent emulsifying capabilities. These findings provide a theoretical basis for the development and utilization of cellulose-based particle stabilizers derived from animal sources.