As a novel temporary consolidant for extracting fragile relics from archaeological sites, menthol has been increasingly applied to many different relics at many excavation sites; however, after relics have been lifted and transported to labs, how to remove previously-used menthol quickly and safely becomes a new challenge. The most commonly-used removal method is to let menthol volatilize naturally, but water also volatilizes when menthol volatilizes. With the loss of water, waterlogged organic relics, which are sensitive to water loss, will have a shrinkage problem. In order to find safe technologies for menthol removal from waterlogged archaeological wood, two types of waterlogged wood relics from the Nanhai Ⅰ shipwreck—bark and rotten wood, which are extremely sensitive to water loss, were taken as examples in our work to test 5 different methods for menthol removal. These methods included natural volatilization, water supplementation+natural volatilization, removal by ethanol, removal by ethanol+water supplementation and water supplementation+heating. The appearance, mass loss and dimensional stability of the tested wood samples were evaluated to select safe methods for menthol removal from waterlogged archaeological wood. The results show that the method of water supplementation worked best for the bark and that of removal by ethanol worked best for the rotten wood. According to the removal effects, ethanol or a combination of ethanol and water are the best methods for the safe removal of menthol from waterlogged wooden relics. This study could provide technological guidance or a reference for archaeologists and conservators in terms of how to remove menthol after its uses for waterlogged archaeological wood.