The mechanical properties of high strength cement-based materials using granulated blast furnace slag (GBFS) as fine aggregate under different curing conditions were studied by experiments. The feasibility of using granulated blast furnace slag as fine aggregate for high strength cement-based materials was discussed. The compressive strength, flexural strength, splitting tensile strength and elastic modulus of high strength cement-based materials using GBFS as fine aggregate under different curing conditions were studied. The effects of microstructure on mechanical properties of the composites under different curing conditions was analyzed by focusing microscope. The test results show that steam curing and autoclave curing can not only improve the early strength of high strength cement-based materials, but also makes the late strength higher than standard curing. The 3d compressive strength of high strength cement-based materials using GBFS as fine aggregate under steam curing conditions increased by 25% compared with standard curing, the 7d compressive strength of high strength cement-based materials using GBFS as fine aggregate under steam curing conditions is higher than the 28d compressive strength under standard curing. And the 3d compressive strength of high strength cement-based materials under autoclave curing can reach the 28d compressive strength under standard curing. By observation of microscopic photographs, under the steam curing, the interfacial transition zone of aggregate and cementitious paste is more compact, under the autoclave curing, aggregate and cementitious paste are blending into one, the interfacial transition zone was dissected.