Understanding the constraint relationship among ecosystem services is significance for the management and optimization of regional ecosystem services. In this study, we estimated the spatial pattern of net primary productivity (NPP), water yield (WY), soil conservation (SC) and wind erosion (WE) service in Horqin Sandy Land during 2000—2018. Then, based on quantile segmentation method to extract the constraint line of four paired ecosystem services, this study discussed the constraint effects between paired ecosystem services and analyzed the key features (including threshold, slope and constant term) of the constraint lines. The results showed that:(1) the average values of NPP, WY, SC and WE in Horqin Sandy Land from 2000 to 2018 were 256.5 gC/m², 211.9 mm, 26.3 t/km² and 3.8 t/m², respectively. Overall, the key ecosystem services increased. Spatially, the increase of NPP were mainly in the southeast and central regions; the WY increased in the south-central regions; the increases of SC centered on northwest and southwest margins; the WE decreased in the central and northern regions and increased in southern sandy land. Due to severe desertification, counties in the south such as Wengniute Banner, Naiman Banner, and Horqin Zuoyihou Banner should be ecologically restored. (2) The constraint lines of NPP-WY, NPP-SC, NPP-WE, WY-SC and WY-WE were parabolic. The constraint relationship between SC-WE was linear. The types of these constraint lines were almost unchanged during 2000-2018. (3) As an amplifier, the NPP is a key service that shaped the strength of the constraint relationship. A slight change of NPP resulted in a large variation of other ecosystem services. The threshold range of constraint line can provide a preliminary basis for a reasonable use of NPP targeting at minimizing the negative constraint effect of NPP on other services. (4) Forest and grassland provided a higher level of soil conservation than farmland. Therefore, in the practice of landscape management, we should focus on the development of grassland and forest ecosystems. What's more, farmland development should be located in the flat areas. It's better to select crop types that require less water and tolerant to drought, so as to improve the overall supply capacity of ecosystem services in the Horqin Sandy Land landscape. Understanding the constraints of ecosystem service pairs and identifying their key characteristics are of great significance for optimization of land use, adjustment of management measures and realization of regional sustainability.