A tethered-wing traction system having: - a traction wing designed to generate a traction force under the effect of the wind, this traction wing having a leading edge and a trailing edge; - a base platform to which the traction wing is connected via a traction line, the traction wing being designed to be deployed and folded in relation to this base platform; - a mooring mast for the traction wing, disposed on the base platform; - multiple folding lines (10A, 10B, 10C) this tethered-wing traction system comprises: - a folding carriage (12C, 12D, 12E) designed to slide along the mooring mast; - a capturing device which is attached to the leading edge of the traction wing and has a fastening arm provided with a fastening rod (27A, 27B, 27C), one of the folding lines (10A, 10B, 10C) projecting in the continuation of the fastening rod (27A, 27B, 27C); the folding carriage (12C, 12D, 12E) having a capturing hook (46A, 46B, 46C) which is movable between a retracted position and a capturing position, in which the capturing hook (46A, 46B, 46C) surrounds the fastening rod (27A, 27B, 27C) characterized in that the folding lines each having an end fixed to the leading edge of the traction wing, the ends being spaced apart from one another along this leading edge. - a traction wing designed to generate a traction force under the effect of the wind, this traction wing having a leading edge and a trailing edge; - a base platform to which the traction wing is connected via a traction line, the traction wing being designed to be deployed and folded in relation to this base platform; - a mooring mast for the traction wing, disposed on the base platform; - multiple folding lines (10A, 10B, 10C) this tethered-wing traction system comprises: - a folding carriage (12C, 12D, 12E) designed to slide along the mooring mast; - a capturing device which is attached to the leading edge of the traction wing and has a fastening arm provided with a fastening rod (27A, 27B, 27C), one of the folding lines (10A, 10B, 10C) projecting in the continuation of the fastening rod (27A, 27B, 27C); the folding carriage (12C, 12D, 12E) having a capturing hook (46A, 46B, 46C) which is movable between a retracted position and a capturing position, in which the capturing hook (46A, 46B, 46C) surrounds the fastening rod (27A, 27B, 27C) characterized in that the folding lines each having an end fixed to the leading edge of the traction wing, the ends being spaced apart from one another along this leading edge. - a folding carriage (12C, 12D, 12E) designed to slide along the mooring mast; - a capturing device which is attached to the leading edge of the traction wing and has a fastening arm provided with a fastening rod (27A, 27B, 27C), one of the folding lines (10A, 10B, 10C) projecting in the continuation of the fastening rod (27A, 27B, 27C); the folding carriage (12C, 12D, 12E) having a capturing hook (46A, 46B, 46C) which is movable between a retracted position and a capturing position, in which the capturing hook (46A, 46B, 46C) surrounds the fastening rod (27A, 27B, 27C) characterized in that the folding lines each having an end fixed to the leading edge of the traction wing, the ends being spaced apart from one another along this leading edge.