In this study, vegetable oil-based high-internal-phase Pickering emulsions (HIPPEs) were formulated from soy protein isolate and sodium alginate, and the effects of different replacement ratios (20–100%) of pork back fat on the quality of emulsified sausages were investigated. With the increase in the fat replacement ratio, cooking loss, released fat, and lipid oxidation significantly decreased (p < 0.05). Similarly, as the replacement ratio rose, L*-values, pH and springiness increased, while a*-values, hardness, cohesiveness, and chewiness showed a significant decrease. The reformulated sausages exhibited superior slice compactness, a macroscopic trait corroborated by the dense network structure observed via microstructural analysis. Electronic nose and electronic tongue measurements indicated that the inclusion of HIPPEs modulated both the aroma profiles and taste attributes of the emulsified sausages. Moreover, although differences were observed in some sensory attributes and flavor characteristics, all formulations with HIPPEs remained within an acceptable sensory range.