<p>This study aims to combine walnut protein isolate (WPI) and chitosan (CS) to prepare nanoparticles, and use them as emulsifiers to stabilize Pickering emulsion to improve the bioaccessibility of curcumin. The average size of WPI-CS nanoparticle (WCN) exceeded that of WPI, accompanied by a reversal of zeta potential from positive to negative, indicating the adsorption of CS molecules onto the surface of WPI nanoparticle. The three-phase contact angle (θ_o/w) of WCN was approximately 27.3°. Upon addition of CS, the θ_o/w of WCN was adjusted to 91.8°, nearing neutral wettability, highlighting the potential of WCN as an effective Pickering emulsifier. Scanning electron microscopy (SEM) illustrated that the presence of chitosan altered the surface and morphology of WCN, resulting in smooth-surfaced WCN with irregular geometrical shapes and larger sizes. Curcumin was successfully encapsulated into the Pickering emulsion stabilized by WCN, with an encapsulation efficiency of 82.53% and a maximum loading capacity of 4.51%. In vitro digestion demonstrated that Pickering emulsions stabilized with WCN enhanced the bioavailability of curcumin while mitigating its degradation. These findings suggest that the WCN effectively stabilizes Pickering emulsions, holding promising applications for nutrient delivery and expands the potential use of WCN in the food industry.</p>