A coupling device (1) for connecting two ends (3, 9) of respective tubular members, allow the opening and the closing of a first tubular member and the simultaneous engagement of the two tubular members, in such a way preventing any pollution, comprises: a first case (5) housing a first end (3) of a respective first tubular member (2), comprising closing means (10) of said first end (3); a second case (20), wherein a flexible terminal section (6) of a respective second tubular member is received, comprising means for driving a second end (9) of said second tubular member from a retracted position to a engagement position into said first end (3) and vice versa; and means for reversibly connecting said first and second cases (5, 20) at a respective coupling port thereof, defining a single sealed environment; wherein the engagement and the disengagement of said second end (9) and the automatic mechanical activation and deactivation of said closing means (10) for opening and closing said first end (3).