The Qinghai Lake Basin, a pivotal ecological region in western China, has experienced substantial land use transformations due to demographic and economic pressures, resulting in significant impacts on its ecosystem service value (ESV). Prior research in this domain has been constrained by a lack of comprehensive spatiotemporal analysis. This study employs an integrated approach utilizing remote sensing technology, geographic information systems (GIS), and meticulous land use evaluations in conjunction with the ESV equivalent factor method to examine changes from 2003 to 2023. The findings revealed a marked reduction in wetland and grassland areas, accompanied by an expansion of construction and cultivated lands, leading to a notable decline in ESV, particularly in areas with high human activity. The primary driver of this decrease in ESV was the loss of wetlands and grasslands, whereas land use changes had differential effects on various ecosystem services (ESs). Notably, water conservation, climate regulation, and biodiversity protection are particularly sensitive to these alterations. This research underscores the importance of adopting balanced land use planning strategies to preserve the regional ESV and offers a robust scientific basis for developing effective ecological conservation and land management policies in the Qinghai Lake Basin and comparable ecosystems.