Hydrogen gas (H2) is an important molecular messenger in animal and plant cells and is involved in various aspects of plant processes, including root organogenesis induction, stress tolerance and postharvest senescence. This study investigated the effect of H2 fumigation on the quality of Lanzhou lily scales. The results indicated the H2 remarkably declined the color variation and browning degree in Lanzhou lily scales by suppressing the activity of phenylalanine ammonia-lyase (PAL), peroxidase (POD) and polyphenol oxidase (PPO). Moreover, H2 significantly alleviated the degradation of soluble proteins and soluble sugars in Lanzhou lily scales during postharvest storage, mitigating the decline in nutritional quality. This alleviating effect of H2 might be achieved by increasing the endogenous H2 concentration. Collectively, our data provide new insights into the postharvest quality reduction of Lanzhou lily scales mitigated by H2 fumigation.