The characteristics of spatial and temporal changes in soil conservation services and the attribution of spatial heterogeneity in the Qilian Mountains were explored, in order to provide scientific reference for the ecological protection and sustainable development of the region. [Methods] Based on the four periods of land use data from 2005 to 2020, combined with topographic, soil and meteorological data, we used the InVEST model and geoprobe method to simulate the soil conservation service, explore the spatial and temporal characteristics of soil conservation and its value, and attribute its spatial heterogeneity. [Results] ①The soil conservation volume in Qilian Mountains area from 2005 to 2020 ranged from 5.02×10⁹ t to 7.89×10⁹ t, with a decreasing trend; the spatial distribution of soil conservation volume was high in the southeast and low in the northwest, and the high value areas were concentrated in the east side of the Qinghai Lake and the Qilian Mountains range in the study area. ② different land use types, grassland soil retention of the largest total amount of soil, forest soil retention intensity was the largest. Soil retention intensity with the increase in elevation was first increased and then decreased in the single peak curve, and with the increase in slope was linearly increasing. ③The average annual value of soil conservation services in the study area was 3.912×10¹³ yuan, with the value of soil fertility conservation E₁ as the main value. ④ The results of geographic exploration showed that slope and soil type had the highest explanatory power for the spatial heterogeneity of soil conservation, and the interaction between vegetation cover and soil type had the highest explanatory power. [Conclusion] Slope and soil type jointly affect vegetation cover, and vegetation cover is the dominant factor influencing the spatial heterogeneity of soil conservation services. It is necessary to convert part of the cultivated land into grassland or woodland, increase ecological protection, improve vegetation cover, reduce soil erosion, increase soil conservation capacity, and thus improve the ecological environment.