Abstract: To address the issues of easy sedimentation and unstable system in chestnut beverages, using centrifugal precipitation rate and static stratification rate as indicators, the optimal complex enzyme components were screened by single factor and orthogonal experiments, and the composite ratio was determined. Then the enzymatic hydrolysis conditions were optimized by response surface methodology, and the effects of complex enzyme hydrolysis on the physicochemical properties, starch structure and volatile compounds of chestnut beverage were analyzed. Results showed that, α-amylase, cellulase, isoamylase, and lipase were the optimal complex enzyme components to improve the stability of chestnut beverage, and the optimal mass ratio was 5:5:4:4, and the optimal enzymatic hydrolysis conditions were confirmed as follows: pH5.0, dosage of 0.69% (w/w), at 56 ℃ for 170 min. After complex enzyme hydrolysis, the centrifugal precipitation rate and static stratification rate were significantly reduced (P<0.05). The contents of glucose and maltose after enzymatic hydrolysis increased significantly (P<0.05). Scanning electron microscopy (SEM) observations revealed that the starch particles were broken, the particle size of starch granules was reduced and the structure became loose after enzymatic hydrolysis. High performance liquid chromatography (HPLC) combined with Nuclear magnetic resonance (NMR) analysis indicated that complex enzyme hydrolysis could enhance the complexity of starch molecular structure, coordinate the chain length distribution and increase the branching degree. Headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) found that the types and contents of volatile compounds increased after enzymatic hydrolysis. The content of alcohols, ketones and hydrocarbons with flower and fruit aroma, fat aroma and other pleasant flavors increased significantly (P<0.05), and the flavor quality was significantly improved. To sum up, complex enzymatic hydrolysis could degrade the macromolecular substances in chestnut, reconstruct the starch structure, improve the stability and flavor of chestnut beverage, which would provide a theoretical basis for improving product quality.