Recovery device of seabed-based observation system without release function and recovery method thereof

The invention belongs to the field of ocean observation, and particularly relates to a recovery device of a seabed-based observation system without a release function and a recovery method of the recovery device. One end of a drag rope is wound on a winch installed on a recovery ship, the other end of the drag rope is connected to one end of a water diversion plate, and the other end of the waterdiversion plate is connected with a recovery net through a mooring rope. The bottom of the recovery net is connected with a bottoming lead block, the top is connected with a floating ball string, a salvage hook is hung on the recovery net, and a tensiometer is installed at the end, close to the recycling ship, of the dragging rope. When the seabed-based observation system is salvaged, the recoveryship drags a bottom supporting device, and when the bottom supporting device pass the seabed-based observation system needing to be salvaged, and the recovery net or the salvage hook drags the seabed-based observation system,