Drylands (areas with an aridity index less than 0.65) are regions characterized by complex human-environment interactions and significant human-land conflicts, making them key areas for studying sustainable development. Mapping the Social-Ecological System (SES) in China's drylands can help identify the basic characteristics of SESs in drylands and propose development paths consistent with key challenges and the Sustainable Development Goals (SDGs). Based on the SES theory and the SDGs framework, this paper constructed a classification framework for SES in China's drylands and applied the Self-Organizing Map clustering method for SES archetype mapping. The temporal dynamics and spatial variations of SES characteristics and SDGs were also analyzed for the years 2000, 2010, and 2020. The results showed that: (1) China's drylands are divided into five SES archetypes: Agricultural and Urbanization Systems (A); Agricultural, Forestry, and Pastoral Zones to Be Developed Systems (B); Grassland Industrialization Systems (C); Oases to Be Developed Systems (D); and Alpine Grassland Fragile Systems (E). (2) In the social-economic subsystem, the three components of economic development level, policy stability, and demographic characteristics, as well as human intervention in the social-ecological interaction subsystem, showed a positive trend across the five SES archetypes. Land resource characteristics and nature's contribution to humans varied considerably across archetypes, with smaller differences in temporal trends. (3) Significant intergroup differences in SDGs were found, with the Agricultural and urbanization systems performing the best; and the Oases-to-be developed systems the worst. The key challenges for each SES archetypes are: A enhancing urban green space and reducing inequality; B addressing imbalances in agro-pastoral structures, excess water use, and technological innovations and transformations. In addition, C, D, and E faced the challenge of upgrading economic development. C integrating emission reductions; D improving ecosystem services and quality of life; and E balancing ecosystem services preservation with fulfilling local survival and livelihood needs. The findings of this study contributed to the formulation of locally adapted sustainable development strategies, suggesting that priority should be given to upgrading the basic needs of the people and overcoming the shortcomings of the SDGs to progressively achieve sustainable development by targeting the key challenges of different SES archetypes.