To investigate the application potential of Monascus strain 2SH in fermented sausages, systematic evaluations were first conducted on its toxigenic properties, growth performance, and processing tolerance, including citrinin production, growth behavior, acid and salt tolerance, and nitrite degradation ability, followed by an assessment of the effects of a Monascus-based composite starter culture on sausage quality and flavor. The results showed that strain 2SH did not produce citrinin and exhibited excellent processing tolerance, being capable of normal growth under stress conditions of pH 3 and 6% salt concentration, with a nitrite degradation rate reaching 97.02%.Using sausage fermented with Lactiplantibacillus sakei 2-Y4-2 as the control, a co-fermentation experiment with L. sakei and Monascus strain 2SH was conducted. Physicochemical analyses indicated that composite fermentation significantly increased total lactic acid bacteria counts (from 8.62 to 8.86 log CFU g?¹) and redness values (from 6.74 to 13.83), while reducing moisture content (from 0.845 to 0.817) and residual nitrite levels (from 2.11 to 1.67 mg kg?¹).Analysis of volatile flavor compounds indicated that co-fermentation with Monascus strain 2SH significantly enriched characteristic flavor components of the sausage, leading to increased levels of key aroma compounds, including 2-octen-1-ol, 2,3-butanediol, decanal, ethyl hexanoate, and (E,E)-3,5-octadien-2-one.In summary, Monascus strain 2SH can significantly improve the physicochemical quality, color attributes, and flavor profile of fermented sausages. It demonstrates good safety and processing compatibility and shows promising application potential in fermented sausage production. These findings provide a theoretical basis and data support for the development of functional fermented sausage products and the advancement of Monascus-based fermentation industries.