Abstract: The spatiotemporal distributions and trends of lightning activity along the Sichuan–Xizang Railway are investigated using data from the World Wide Lightning Location Network (WWLLN) for the period 2010–2019, considering the relative detection efficiency of the network. The results indicate that the temporospatial distributions over the Sichuan–Xizang Railway sections below 3000 m elevation of the Qinghai–Xizang Plateau (QXP) (from Chengdu west station to Yaan station) differ significantly from those above the 3000 m elevation (from Yaan station to Lhasa station). First, the spatial distribution of the mean flash density is higher in the eastern sections of the railway, averaging 50 fl (10 km)⁻² a⁻¹, than in the western sections, for which the mean flash density is 10 fl (10 km)⁻² a⁻¹. Second, the lightning activity around sections above the 3000 m elevation manifests earlier (in May) and ceases later (in November), whereas the lightning activity below 3000 m occurs from June to October. Third, the sections above the 3000 m elevation experience peak diurnal lightning activity in the afternoon (1600 BJT–2000 BJT), while the sections below the 3000 m elevation experience peak activity early in the morning (0000 BJT–0600 BJT). In terms of the long-term trends, the increase in the lightning density amplitude along the Sichuan–Xizang Railway is more pronounced than the decrease. Specifically, most areas of the railway above 3000 m elevation exhibit an upward trend in flash density exceeding 14 fl (10 km)⁻² a⁻¹, indicating an increase of more than 70%. The lightning density around Lhasa station has increased by up to 150%. The stations below 3000 m (Chengdu west to Yaan station) show significantly different lightning densities, exhibiting a decreasing trend approximately −10 fl (10 km)⁻² a⁻¹, a decrease of 60%.