Abstract: In order to get more suitable hydraulic lime materials for stone and earthen historical relics reinforcement conservation, the slag, admixtures and polyvinyl alcohol fiber modified hydraulic lime mixture proportion optimization design, physical mechanical properties, mechanism of hydration hardening and durability were studied in this paper. The researches show that adding slag, admixtures and polyvinyl alcohol fiber can significantly improve the samples’ physical mechanical properties and durability. The flexural strength, compressive strength and pull strength of the modified hydraulic lime sample D had reached at 3.27, 15.45 and 0.61MPa, respectively. Moreover, after the water, salt and dry-wet cycle tests, the sample D still keeps high mechanical properties, which have important implications for conservation and restoration of the stone and earthen historical relics.