Surveying and mapping device for collecting thickness of underwater sludge

The invention discloses a surveying and mapping device for collecting the thickness of underwater sludge, and relates to the field of sludge surveying and mapping, the surveying and mapping device comprises a hook, a connecting rod, a mounting plate and a contraction part, the contraction part comprises a plurality of mounting blocks fixedly mounted on the mounting plate, and the plurality of mounting blocks are jointly and rotatably connected with the lower end of the hook through the connecting rod; and a mounting cylinder is fixedly mounted at the lower end of the mounting plate. The device has the advantages that sludge thickness surveying and mapping can be conducted on the bottoms of water areas with different depths, meanwhile, the sludge deformation degree caused by the gravity of the device can be effectively reduced during surveying and mapping, the surveying and mapping result of the device is more accurate, the whole device can be effectively protected through the arranged shrinkage plate, and aft