Rice bran protein fibrils (RBPFs) and chitin nanofibers (CNFs) have great untapped application potential in fat and salt reduction. The present study aims to prepare RBPF-CNF complexes at the optimum conditions and investigate their structures and physicochemical properties. RBPFs and CNFs formed better fiber structures with the higher viscosity and saltiness when heated for 10 h and ultrasound treated for 40 min, respectively. Transmission electron microscopy results suggested that the structure of RBPFs gradually degraded with increasing pH, and the addition of CNFs improved their stability. Analysis of zeta potential, free sulfhydryl, secondary and tertiary structures, surface hydrophobicity and chemical forces confirmed that CNFs increased β-sheet contents in RBPFs, and that electrostatic interactions, hydrophobic interactions and hydrogen bonds dominated between RBPFs and CNFs. Rheological and emulsification showed that the CNFs increased the viscosity, storage modulus (G'), loss modulus (G"), emulsifying activity index and emulsifying stability index of RBPF solution, especially at pH = 5 and RBPF/CNF ratio of 2:1. At this pH and ratio, the release of sodium in vitro, saltiness sensory evaluation and electronic tongue analysis showed that the complex had the highest release content and rate of sodium and strongest saltiness, capable of increasing saltiness by at least 2-fold. Principal component analysis and correlation analysis verified the consistency of sensory evaluation and electronic tongue detection in saltiness analysis. Overall, CNFs improved the structural stability, physicochemical and functional properties of RBPFs. The RBPF-CNF complexes can be used as a novel thickener, emulsifier and saltiness-enhancer to further prepare low-fat and low-salt food.