Abstract: There exists a trade-off and synergy relationship between various ecosystem services of ecological spaces, and ecological space planning aiming at providing multiple ecosystem services or ecological products is essentially a multi-objective elastic decision-making process under spatial constraints. This research, by virtue of the geographical simulation and optimization systems (GeoSOS) space optimization technology platform, proposes a strategy for demarcation and elastic grading of ecological space that aims at synergistic benefits of multiple ecosystem services while taking into account spatial systematicness. Taking Qixia City in Shandong Province as an example, the research measures the three dominant ecosystem services of biodiversity maintenance, water supply and carbon regulation using the integrated valuation of ecosystem services and trade-offs (InVEST) model. Based on the spatial optimization technique and multi-scenario analysis, it demarcates four types of ecological spaces and provides targeted recommendations for control thereof based on elastic gradings, such as systematic protection and rigid control, structure stabilization and development limitation, ecological reservation and moderate development, as well as service optimization and flexible control. It can provide a theoretical basis for the formulating of ecological control strategies and zoning plans.