The invention relates to a marine magnetic survey device for polar floating ice areas. The device comprises an underwater task execution unit, an onboard measurement and control unit and a coaxial armor cable. The underwater task execution unit is connected with the onboard measurement and control unit through the coaxial armor cable; the underwater task execution unit comprises a towed body, an underwater acquisition control unit, an underwater modem, a sensor, a magnetic tow, a magnetic probe and a power supply unit; the onboard measurement and control unit comprises a deck acquisition and control unit and a deck modem; a sealed control cabin, a sealed power supply cabin and the sensor are mounted inside the towed body; the underwater acquisition control unit and the underwater modem are mounted in the sealed control cabin, and the power supply unit is mounted in the sealed power supply cabin; the underwater acquisition control unit supplies power to the magnetic probe and acquires signals of the magnetic probe and the sensor. The device has the advantages that threat of floating ice to equipment safety is lowered greatly, risk of equipment loss and damage is lowered, and polar-region magnetic survey efficiency is improved.