Emulsion gel is a class of soft-solid material that combines the beneficial characteristics of both biopolymer hydrogel and Emulsion. This type of edible soft-solid material can be used to create novel food products or to improve the texture and sensory of existing products. Furthermore, emulsion gel was proven to be good delivery systems for functional ingredients, either hydrophobic or hydrophilic. The macroscopic physicochemical properties of emulsion gels (such as appearance, texture, and stability) depend on the type, concentration, organization, and interactions of their structural elements, such as oil droplets, proteins, polysaccharides, and crosslinking agents. Therefore, the functional performance of emulsion gels can be tailored by selecting different structural elements and processing conditions to fabricate them. Whey protein isolate (WPI) contains a mixture of globular proteins isolated from the whey fraction of milk. WPI is widely used as a functional ingredient in the food industry because it exhibits good emulsification, foaming, thickening, gelation, water holding, and structure formation properties. Recent investigations have shown that the unfolding and aggregation of protein molecules is affected by polysaccharides. The protein-polysaccharide interactions determine the adsorption of polymers at the interface, and the affinity between the oil droplets and the gel matrix, thus affecting both the microstructure and the rheological behavior of an emulsion gel. Hyaluronic acid (HA) is a non-sulfated linear glycosaminoglycan. HA solution has good thickening and gel-forming behaviors because of its ability to modulate the rheological properties. The properties of HA also vary with different concentrations and molecular weights. Therefore, we leveraged the respective advantages of HA and WPI to design a protein-polysaccharide emulsion gel system, creating a protein-polysaccharide food material with excellent 3D printing performance. The emulsion gels were fabricated using the combination of cold-gelation and cross-linking with transglutaminase. The emulsion gels of varying strength were fabricated by incorporating HA with different molecular weights (100 kDa、300 kDa、1000 kDa) and concentrations (0.25 %、0.5 %、0.75 %、1 %). Their physical, structural, and functional properties were subsequently characterized using scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), rheological analysis, particle size and zeta potential measurements, fourier transform infrared spectroscopy (FTIR), texture profile analysis, water holding capacity (WHC) and freeze-thaw stability. The results indicated that the molecular weight and concentration of HA affect the gel strength. The addition of HA significantly changed the conformation of WPI, enhanced its adsorption capacity at the oil droplet interface, and improved its emulsification properties through electrostatic interactions and steric hindrance effects. Furthermore, due to strengthened hydrogen bonding and hydrophobic interactions, WPI-HA emulsion gels exhibited better textural properties and a more uniform and dense network structure compared to emulsion gels formed with WPI alone. Adding low molecular weight HA can form gels with better mechanical strength. The emulsion gel containing 0.5 % of 100 kDa HA showed excellent rheological properties. By applying an emulsion gel of 0.5 % of 100 kDa HA to 3D printing, the printed models exhibited excellent printing accuracy and self-supporting properties. This study helped to reveal the rheological and stability mechanisms of WPI-HA emulsion gels, provided a broad foundation for the rapid development of food-based 3D printing materials, and also aided in designing new food materials with novel or improved textural and sensory properties.