Understanding the dietary composition of the Siberian musk deer (Moschus moschiferus) is critical for informing conservation efforts, particularly given the species’ vulnerable status in the Republic of Korea and its limited ecological data. Previous dietary studies have relied on conventional methods with limitations in taxonomic precision, hindering comprehensive insights into their feeding ecology. To address this gap, we used Next-Generation Sequencing to analyze 16 fecal samples collected in April from Gangwon Province, the habitat of M. moschiferus. Our results revealed 213 unique plant species, with Morus, Quercus, and Prunus accounting for the majority of the diet. Notably, nearly half of the identified genera, including Morus, Actinidia, and Viscum, were reported for the first time as dietary plants of M. moschiferus. This study confirms that M. moschiferus is a concentrate feeder that primarily relies on woody plants (98.8%) and may exhibit tree-climbing behavior to access parasitic shrubs like Viscum. These findings provide a foundation for future dietary analysis research and serve as valuable baseline data for the long-term conservation of M. moschiferus.