Water content is one of the most commonly-used physical parameters to assess the deterioration of waterlogged archaeological wood. Currently, popular methods for the determination of water content include the drying method, the resistance method, near-infrared spectrometry, etc. However, these methods are either destructive or not applicable due to determination ranges. In order to find a non-destructive method suitable for the determination of water content of waterlogged archeological wood, relationships among water content, wet density and ash content of waterlogged wood were established in our study. Accordingly, we put forward a convenient method, called the “solution density method” to determine water content. Samples unearthed in Tianchang, Huaibei and other places were tested using this method. It was found that the data from this method, compared with standard values (obtained using dry method) were quite close (relative error within 10%), which demonstrates its reliability. A further study showed that the more the wood had deteriorated, the smaller the relative error was, indicating that this non-destructive method is more suitable for waterlogged wood with serious degradation.