The impact of moisture content on the structure and physicochemical properties of textured protein, as well as on the quality of vegetarian ham sausages was evaluated. Soybean protein was used as the main raw material and changes in the color, texturization, textural properties, microstructure, and secondary structure of textured soybean protein, as well as the sensory quality and texture characteristics of vegetarian ham sausage, were evaluated under different moisture content. With the increase in moisture content, the degree of texturization showed a trend of initial increase, followed by a decrease, peaking (1.55) at a moisture content of 50% (m/m). Hardness and chewiness decreased significantly from 3 423.12 and 2 135.44 g at 40% (m/m) moisture content to 886.37 and 417.44 g at 50% (m/m) moisture content, respectively (P<0.05). Scanning electron microscopy showed that textured protein prepared at 50% moisture content (m/m) had a more fiber structure and that increase in moisture content promoted the transition from β-turns to β-sheets. The sensory quality of vegetarian ham sausage prepared using textured protein with 50% (m/m) moisture content was similar to that of meat sausage. Collectively, this study provides a theoretical basis for further understanding the physicochemical events mediating textured proteins formation and the development of related products.