The invention discloses a river channel desilting device for water conservancy projects, and belongs to the technical field of water conservancy projects, the river channel desilting device comprises a collecting box used for storing
sludge, a
sludge pump is fixedly mounted at the top of the collecting box, and a feeding
pipe and a discharging
pipe are respectively communicated in a feeding port and a discharging port of the
sludge pump; the extraction mechanism is used for extracting sludge, and the extraction mechanism comprises a mounting seat, an extraction
pipe and a connecting pipe; the
dewatering mechanism is used for
dewatering sludge and comprises a collecting hopper and a
dewatering cylinder, a conveying shaft is rotatably mounted in the dewatering cylinder, a spiral
auger is fixedly mounted on the outer side of the conveying shaft, and the collecting hopper is slidably connected to the upper portion of the dewatering cylinder. Through the cooperation of the extraction mechanism and the
dehydration mechanism, automatic extraction and
dehydration of river
silt can be achieved, the crushing mechanism is matched to achieve
cutting and scattering of the
silt, the
scattering effect can be adjusted according to the flowing degree of the
silt, the fluidity of the silt is improved, silt blockage is avoided, and the desilting efficiency is improved.