The utility model discloses a deep-sea installation device for submarine storage tanks, and belongs to the technical field of marine engineering. The problem of difficulty in deep-sea installation of large submarine structures such as the submarine storage tanks exceeding conventional floating crane and rope joint capacity is solved. The deep-sea installation device for the submarine storage tanks comprises a lifting frame, a heave compensator, a handling winch, an oil supply ship and a packing fluid charging and discharging pipeline. During offshore installation, light weight fluids such as oil are filled in the storage tanks, and additional inertial force caused by shaking of ships and the like is reduced by the heave compensator. By means of reasonable combination of existing equipment, the deep-sea installation device solves the problem that large facilities with the weight exceeding kilotons cannot be installed in deep sea in the past, internal pressure and external pressure are automatically balanced by filling oil, the structural design is easily realized, and heave compensators are serially connected for hoisting, so that the influence of environmental factors on equipment such as a floating crane and the like can be reduced when large underwater facilities are installed.