Extensive eucalyptus introduction alters land use patterns and ecosystem services (ES). Understanding ecosystem service supply-demand (SDES) relationships is therefore crucial for regional sustainability. Focusing on Lancang County, a key eucalyptus planting area, this study employed a framework integrating land use change analysis, SDES assessment, optimization, and zoning. We evaluated ES supply/demand, analyzed SDES dynamics under different land uses, simulated natural development and optimal scenarios for land use optimization, and proposed zoning strategies to enhance SDES alignment. Key findings: (1) Dominated by forest and dry land, Lancang experienced significant land use shifts, notably dryland-to-forest conversions (similar to 50 %), heavily influenced by large-scale eucalyptus introduction. (2) Overall ES supply exceeded demand, but spatial mismatches existed; SDES relationships varied significantly with land use. (3) Based on SDES relationships and FLUS modeling, land was zoned into Conservation and Development, Priority Transfer, and Restricted Transfer areas. Optimization identified dry land, shrubland, and unused land as suitable for future eucalyptus cultivation under zoning regulations.