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) 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 furling line connected to the trailing edge of the traction wing; this tethered-wing traction system being characterized in that it has: - a mooring carriage designed to slide along the mooring mast and controlled by a slide actuator, this mooring carriage having an engagement interface designed to keep the leading edge of the traction wing moored; - a folding carriage (12C, 12D, 12E) designed to slide along the mooring mast and controlled by a slide actuator (66C, 66D, 66E), this folding carriage (12C, 12D, 12E) having capturing means (46A, 46B, 46C) designed to capture at least one folding line (10A, 10B, 10C); - a furling carriage designed to slide along the mooring mast and controlled by a slide actuator, this furling carriage having capturing means designed to capture the furling line; - a control module for controlling said slide actuators (66A, 66B, 66C, 66D, 66E), this control module having at least the following two modes of operation: a folding mode in which the mooring carriage and the folding carriage (12C, 12D, 12E) are moved away from one another; a furling mode in which the furling carriage and the mooring carriage are moved away from one another. - 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) 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 furling line connected to the trailing edge of the traction wing; - a mooring carriage designed to slide along the mooring mast and controlled by a slide actuator, this mooring carriage having an engagement interface designed to keep the leading edge of the traction wing moored; - a folding carriage (12C, 12D, 12E) designed to slide along the mooring mast and controlled by a slide actuator (66C, 66D, 66E), this folding carriage (12C, 12D, 12E) having capturing means (46A, 46B, 46C) designed to capture at least one folding line (10A, 10B, 10C); - a furling carriage designed to slide along the mooring mast and controlled by a slide actuator, this furling carriage having capturing means designed to capture the furling line; - a control module for controlling said slide actuators (66A, 66B, 66C, 66D, 66E), this control module having at least the following two modes of operation: a folding mode in which the mooring carriage and the folding carriage (12C, 12D, 12E) are moved away from one another; a furling mode in which the furling carriage and the mooring carriage are moved away from one another.