Device for the towing vehicle-trailer connection, comprising: - at least a first male joint connectable to the braking system of a trailer, inside said first male joint being provided first valve means movable between a closed position and an open position wherein they prevent and allow the passage of a work fluid, respectively; - at least a first female joint connectable to the braking system of a trailer and adapted to receive said first male joint; - at least a second male joint connectable to the automatic and/or parking brake of a trailer, inside said second male joint being provided second valve means movable between a closed position and an open position wherein they prevent and allow the passage of a work fluid, respectively; wherein said second valve means comprise at least one plugging element housed in a sliding manner inside said second male joint between said closed position and said open position, - a brake-trailer valve comprising a body wherein at least one seat is formed communicating with a supply port connectable to a source of a work fluid at a first pressure, and with at least one discharge port of the work fluid; - at least one distributor housed in a sliding manner inside said seat and movable at least to place said first male joint in communication with said supply port or with said discharge port; - piloting means of said distributor which are connectable to the braking system of a towing vehicle and comprising at least a first and a second piloting element (11a, 11b) which are adapted to interact with said distributor; - control means operable by said second valve means and movable between a home position, wherein they allow the displacement of both said piloting elements (11a, 11b), and a work position, wherein they are adapted to lock the displacement of one of said piloting elements (11a, 11b), said second valve means comprising at least one thrust element housed in a sliding manner inside said second male joint and adapted to interact with said control means; where said thrust element is movable in a sliding manner with respect to said plugging element and has at least a first end facing outwardly of said second male joint and a second end, opposed to said first end, able to interact with said control means; characterized by the fact that it comprises at least a second female joint connectable to the braking system of the trailer and adapted to receive said second male joint; wherein said second female joint comprises at least one abutment element defining an abutment surface which is adapted to interact with said plugging element to displace it from the closed position to the open position following the insertion of said second male joint, and by the fact that said first end is adapted to operate in conjunction with said abutment element. - at least a first male joint connectable to the braking system of a trailer, inside said first male joint being provided first valve means movable between a closed position and an open position wherein they prevent and allow the passage of a work fluid, respectively; - at least a first female joint connectable to the braking system of a trailer and adapted to receive said first male joint; - at least a second male joint connectable to the automatic and/or parking brake of a trailer, inside said second male joint being provided second valve means movable between a closed position and an open position wherein they prevent and allow the passage of a work fluid, respectively; wherein said second valve means comprise at least one plugging element housed in a sliding manner inside said second male joint between said closed position and said open position, - a brake-trailer valve comprising a body wherein at least one seat is formed communicating with a supply port connectable to a source of a work fluid at a first pressure, and with at least one discharge port of the work fluid; - at least one distributor housed in a sliding manner inside said seat and movable at least to place said first male joint in communication with said supply port or with said discharge port; - piloting means of said distributor which are connectable to the braking system of a towing vehicle and comprising at least a first and a second piloting element (11a, 11b) which are adapted to interact with said distributor; - control means operable by said second valve means and movable between a home position, wherein they allow the displacement of both said piloting elements (11a, 11b), and a work position, wherein they are adapted to lock the displacement of one of said piloting elements (11a, 11b), said second valve means comprising at least one thrust element housed in a sliding manner inside said second male joint and adapted to interact with said control means;