Abstract: A hydraulic connecting device is disclosed, the device being for interconnecting a multi-line hose and a coupling device. The hose has a plurality of flexible hydraulic conduits bunched together within a protective sheath. The coupling device has a plurality of plug pins held within a casing by a retaining disc. The casing is attached to the protective sheath by the connecting device. The connecting device is constituted by a clamping sleeve, which is connected to the protective sheath, and a connecting sleeve, which is connected to the casing. The two sleeves are telescoped together at end portions thereof and are joined together by means of a rotary connection which resists tensile forces. The rotary connection is constituted by a releasable securing element.