Abstract: A mud removing device includes a case which is merged into water and has an opening and a space. At least one at suction tube and multiple injection tubes respectively extend and connect to the case. The injection tubes are located around the opening of the case and one end of the injection tubes reaches to the periphery of the opening. A working station introduces high pressure water to flush the mud located below the opening of the case and at least one the suction tube sucks the mud which is collected to the working station. The case has weights and the working station can be carried by a floating carrier. The working station has a crane which has a cable to hang the case.