This study investigated the optimization of formulations for dairy beverage supplemented with an extruded mixture of Tremella funciformis and five grains using one-factor-at-a-time and orthogonal array design methods. The sensory evaluation score and stability of the beverage were evaluated as a function of the amount of the extruded product, sieve mesh size used on the powdered extrudate and the amount of the composite stabilizer. Changes in the rheological properties and particle size distribution of the beverage during 7 days of storage at 4, 25 and 37 ℃ were measured by a rheometer and a particle size analyzer, respectively. The optimum process conditions were determined as follows: adding extrudate at 5% and the composite stabilizer at 0.4% and sieving the extrudate through a 160-mesh sieve. The sensory evaluation score and stability of the beverage produced under the optimized conditions were (90.14 ± 0.32) points and (92.27 ± 0.07)%, respectively. After storage at 4, 25 and 37 ℃, the beverage was characterized as a pseudoplastic fluid in static rheology and as a weak gel in dynamic rheology. After storage at 4 ℃, the viscosity coefficient and particle size distribution were similar to those before storage. To maintain its taste and shelf life (up to 180 days), the beverage should be stored at 4 ℃, and cold chain distribution is recommended for it.