Abstract: Lithium, a strategic and critical metallic mineral, is currently a prominent focus of mineral exploration. Among all lithium resources, the pegmatite lithium deposits have emerged as a significant exploration target. Remote sensing technology has played a significant role in the preliminary stages of lithium exploration, which primarily relied on high-resolution and hyperspectral satellite data. In recent years, the application of airborne hyperspectral remote sensing technology, which combines high spatial and spectral resolution, has further enriched the remote sensing data sources. However, the applicability of these multi-source optical remote sensing data in the exploration of pegmatite lithium deposits remains to be systematically and comparatively analyzed. Consequently, there exists a continued debate concerning the feasibility of remote sensing technology in directly detecting lithium-bearing pegmatite veins or lithium minerals. Hence, focusing on the Kuerqimuke lithium deposit in Qinghe County, Altay region, this study comparatively analyzed the sub-meter high-resolution data, hyperspectral satellite data, and airborne hyperspectral data in multi-source remote sensing detection. The results indicate that the sub-meter high-resolution data played a critical role in revealing the spatial distribution of pegmatite veins but failed to distinguish lithium-bearing veins from non-lithium-bearing veins. The hyperspectral satellite data served as a useful supplementary tool for identifying large-scale lithium-bearing veins; however, they generally struggled to directly reveal spodumene information due to the low spatial resolution. In contrast, the airborne hyperspectral data, characterized by high spatial and spectral resolution, demonstrated significant technical advantages in exploring pegmatite lithium deposits. They enable accurate identification of spodumenes under the condition that parameters such as the central wavelength, spectral resolution, and sampling interval meet specific requirements. Overall, this study provides a practical reference for applying optical remote sensing data in exploring pegmatite lithium deposits.