The Zhidan Yuan sluice ruins dating from Yuan Dynasty is the best preserved and largest Chinese water construction heritage. It is well-structured and has exquisite workmanship. The wooden stakes, gates, and boards all need conservation. This article describes the preliminary work to conserve the wooden objects of the sluice ruins. The properties of water, soil and all kinds of wooden material, the status of the objects, and harmful organisms were analyzed. In the process of excavation, onsite sterilization was performed, and the excavated areas were backfilled to protect the gate and threshold. Onsite dehydration was also tested for wooden stakes.