The key development technology of nautical depth is how to use the silty back silting layer under current water depth as navigation channel in order to increase the navigation depth and reduce the maintenance costs. The sampling technique used in silty harbor or the silt characteristics nautical back silting layer is mainly devided into categries of non-contact detection and contact sampling both in China and abroad. At present, the non-contact detection technique represented by Dutch Silas system has been mature, which has been widely applied worldwide; while there is no significant breakthrough in contact detection technique in back silting layer. In engineering practice, the detection data by non-contact technique should be verified. It is necessary to develop a stable and efficient sampler for undisturbed silty soil sampling and the contact sampling technique should be enriched and perfected.