The invention relates to matched equipment of a submarine cable inbuilt machine hanging and dragging system of a cable laying ship, in particular to a steel wire rope connection device used for a submarine cable inbuilt extension and retraction system comprises a steel wire rope connector, side plates, a bent plate assembly, mooring rope columns and steel wire rope baffles, wherein one end of the steel wire rope connector is provided with a steel wire rope connected with an extension and retraction A-type frame and the side plates are arranged on the two sides of the other end of the steel wire rope connector; the other end of the steel wire rope connector is hinged with one end of each of the two side plates; one end of the bent plate assembly is located between the two side plates and is hinged with the other ends of the two side plates; the mooring rope columns are arranged on the two sides of the other end of the bent plate assembly; the steel wire rope baffle is connected with the outer side of each mooring rope column; steel wire ropes which are connected with a submarine cable inbuilt machine are hung on the mooring rope columns on the two sides of the other end of the bent plate assembly. By the aid of the steel wire rope connection device used for a submarine cable inbuilt extension and retraction system, the connection transition problem of the steel wire ropes from the extension and retraction A-type frame to the submarine cable inbuilt machine are effectively solved, the service life of the steel wire ropes of a transition part is prolonged, and an extension and retraction working process is more stable and safer.