Abstract: To effectively utilize the substantial by-product, whey, generated during the processing of characteristic dairy product milk dregs on the Qinghai-Tibet Plateau, this study utilized whey from Senburi Village, Gagong County, Shannan City, Tibet, as the raw material to prepare a kefir-fermented beverage. The effects of different sterilization methods and sucrose addition levels on the storage stability, sensory characteristics, and in vitro antioxidant activity of the whey beverage during storage (4 ℃)were systematically investigated. Results indicated that post-fermentation sterilization significantly (P<0.05) slowed the decrease in pH, reduced the centrifugal sedimentation rate, and the 1,1-diphenyl-2-picryhydrazinyl (DPPH) free radical scavenging rate of whey beverages, while enhancing viscosity and the scavenging rate of 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS⁺). Under set sterilization conditions, the beverages with 9% (w/w) sucrose exhibited the fastest acidification rate (P<0.05) and the lowest (P<0.05) centrifugal sedimentation rate on day 28 of storage, alongside the highest (P<0.05) apparent viscosity and free amino acid content. In contrast, the sugar-free formulation demonstrated significantly higher (P<0.05) DPPH and ABTS⁺ free radical scavenging rates than other groups on the first day of storage, recorded as (95.28±3.29)% and (63.58±0.11)%, respectively. Consequently, the beverage with 9% sucrose undergoing post-fermentation sterilization demonstrated optimal storage stability and sensory acceptance, while the sucrose-free formula was more beneficial for enhancing antioxidant function. This research provides novel insights for enhancing the efficient utilization of whey resources in Tibet, exploring sustainable development models for the whey industry, and diversifying the functional beverage market.