A self-anchored piling sediment sampler belongs to the technical fields of environmental monitoring, environmental government and sediment sample collection. The sampler is mainly composed of a sampling tube mechanism, an anchor rack mechanism and a cable. A drainer is designed to realize automatic drainage and air seal, so that an anchor socket can form a good anchoring condition with sediments during collection, thereby providing a stable sampling condition in cooperation with adjustable self gravity. The drainer is also applied in the sampling tube mechanism, thereby facilitating collection and seal of sediment samples. At the end of sampling, a water injector can eliminate suction force of the sediments and alleviate resistance in a lifting process. The cable is fixed to an outer sampling tube by fixed pulleys A, clamping hooks and fixed pulleys B placed on fixing rods so as to realize the conversion of the pulling force into the pressure on the sampling tube and provide sampling power. Thus, the collecti