By investigating the distribution of diatoms in major waters within Yushu Tibetan Autonomous Prefecture, Qinghai Province, a database of diatoms was established to support the diagnosis of drowning. In 2023, water samples were collected from two lakes and three rivers (totaling six water collection points) of Yushu in spring, summer, autumn, and winter respectively. The diatom genera were quantitatively analyzed using graphite ablation-vacuum filtration-automated scanning electron microscopy detection. A total of 66 genera of diatoms and one genus of golden algae were detected in the collected samples. Among these, there were 5 dominant genera, 34 genera that could be detected throughout the year, 24 genera that could be detected at each site, and 18 genera that were found to be seasonally or regionally specialized. The composition of diatoms at each site was found to be significantly different both seasonally and regionally (P<0.01). In this paper, the graphite digestion-vacuum filtration-automated scanning electron microscopy detection method was applied to enhance the richness of diatom survey data. The species composition and distribution of diatoms in the main waters of Yushu exhibit local characteristics, and it is necessary to establish a diatom database to support the examination, identification, and detection of drowning cases.