In order to realize the high-value utilization of low-value fish products, this study prepared the silver carp hydrolysate by enzymatic hydrolysis, and constructed the Maillard reaction (MR) system with xylose to study the effect of ultrasound-assisted MR on the flavor characteristics of the hydrolysate, and compared with the traditional wet MR and enzymatic hydrolysis. The results showed that the ultrasonic pretreatment could promote the generation of intermediates and the degree of browning and improve the rate of the MR; the fluorescence intensity of the hydrolysate decreased after the MR, indicating the introduction of hydroxyl groups. Compared with the hydrolysate, the bitter amino acids of the ultrasound-assisted Maillard reaction products (MRPs) were reduced by 18%, which was better than the un-sonicated group. The results of MMSE-GC-MS and electron tongue showed that the volatile compounds (benzaldehyde, furfural and 2-ethylfuran, etc.) of the ultrasound-assisted MRPs contributed to the aroma enhancement were higher in the products, and the bitterness and astringency were lower than those of the hydrolysate and the MRPs. The above results indicate that the ultrasonic treatment can effectively improve the flavor characteristics of the hydrolysate and provide a reference for the development of freshwater fish products.