The present study explored the modification of rice starch via dielectric barrier discharge cold plasma (DBD-CP) employing air and argon as the input gas, followed by complexation with stearic acid to yield modified rice starch-stearic acid complexes. The complexes were characterized by a V-type crystalline structure, exhibiting enhanced thermal stability and hydrophobicity compared to conventional rice starch-stearic acid complexes. Utilization of argon as the input gas markedly improved the modification effects on complexes over air, as evidenced by a further increase in the water contact angle to 78.99°, an ergosterol encapsulation rate of 50.91%, and an in vitro digestive release rate of 70.84% within the prepared Pickering emulsion. These findings indicate the significant potential of DBD-CP pretreatment with argon for enhancing the physicochemical properties of starch-fatty acid complexes, particularly in the formulation of Pickering emulsions with improved emulsifying capacities.