This study utilized zein as the core material and flaxseed gum (FG) as the coating material to prepare composite nanoparticles via the anti-solvent precipitation method. The results demonstrated that the nanoparticles prepared with 20 mg/mL zein and 0.2 mg/mL FG exhibited the best stability and uniformity, with a particle size of 81.98 nm, polydispersity index (PDI) of 0.25, and zeta potential of -37.69 mV. Fourier transform infrared spectroscopy (FTIR) analysis indicated that hydrogen bonding, electrostatic interactions, and hydrophobic interactions were the primary driving forces for zein-FG formation. X-ray diffraction (XRD) analysis revealed the presence of interactions between FG and zein. Furthermore, the incorporation of FG into zein nanoparticles enhanced its salt ion, pH, and storage stability. In conclusion, zein-FG nanoparticles show potential as novel materials for developing high-efficiency nanodelivery systems.