Objective This study aims to optimize the processing technology of Cordyceps militaris polysaccharide （CMP） fermented milk.Method Single-factor experiments and response surface methodology （RSM） were employed to refine the production parameters. Product quality attributes were also analyzed.Result The optimal conditions were determined as follows： pure milk （250 mL）， xylitol （35.3 g）， CMP （3.8 g）， starter culture （0.4 g）， cashew fragments （15.0 g）， and fermentation at 42 °C for 10 h. Under these conditions， the sensory score reached 90 points， aligning closely with the predicted value （89 points）. Acidity analysis revealed no significant difference between the experimental and control groups（P>0.05）， both conforming to national standards. Chromaticity tests revealed that CMP supplementation significantly reduced product brightness （L*） while enhancing red （a*） and yellow （b*） tones， imparting a distinctive color to the fermented milk.Conclusion These findings provide support for the development of functional fermented milk products.