The sustainability of pre-conservation provides the possibility for the sustainable development of world cultural heritage conservation. In the preliminary stage of pre-conservation of Suzhou’s classical gardens, taking the Humble Administrator’s garden as the research object, this paper analyzes the disadvantages of the Humble Administrator' s Garden' s existing conservation system. It has been explored the pre-conservation measures focusing on its spatial characteristics. It puts forward strategies of the spatial layout, spatial structure, and artistic conception to provide some theoretical reference to the Humble Administrator’s Garden’s existing protection system and further promote sustainable protection of world cultural heritage.