Fluid connection device for connecting a first fluid conduit to a second fluid conduit, comprising: - a female plug, made of plastic and joined to the first fluid conduit, - a male plug, made of plastic, joined to the second fluid conduit, and intended for insertion into the female plug into a final coupling position, according to a coupling/decoupling movement parallel to an axial direction, - a movable primary locking device able to move transversely between two positions, arranged on the female plug and forming a part separate from the female plug and separate from the male plug, having a locked position in which it prevents the male and female plugs from being released from the final coupling position, the primary locking device being embedded and trapped on the female plug in a sliding manner transversely to the axial direction, the primary locking device being provided in the form of a plate arranged transversely to the axial direction, with a manipulating portion arranged perpendicular to said plate, the plate comprising a substantially circular central hole of a slightly larger diameter than the diameter of the male plug, at least one projection or rim being provided in a lower portion of the hole and intended to be received in an annular groove of the male plug, the projection or rim bearing against a shoulder formed on the male plug, which ensures a retraction-preventing locking function, - a movable secondary lock having an active position adapted to prevent the primary locking device from being moved from its locked position, the secondary lock being a separate part able to be interposed, in its active position, in a manner that prevents movement of the primary locking device, the secondary lock being configured to be irreversibly clipped into place in its active position, whereby the fluid connection device establishes a permanent, non-separable connection of the first and second conduits, for ensuring that the chain of sterility remains intact, wherein the secondary lock can only be placed in its active position if the primary locking device is in its locked position, the secondary lock preventing the primary locking device from moving out of its locked position; characterized in that the secondary lock is a piece able to be supplied and moved separately from the male and female plugs (1, 2), such that the female plug and the male plug can be assembled together in their final coupling position when the primary locking device, trapped in the female plug, is present and in the absence of the secondary lock, and in that the female plug is adapted to receive the secondary lock, selectively after obtaining the final coupling position and after obtaining the locked position. - a female plug, made of plastic and joined to the first fluid conduit, - a male plug, made of plastic, joined to the second fluid conduit, and intended for insertion into the female plug into a final coupling position, according to a coupling/decoupling movement parallel to an axial direction, - a movable primary locking device able to move transversely between two positions, arranged on the female plug and forming a part separate from the female plug and separate from the male plug, having a locked position in which it prevents the male and female plugs from being released from the final coupling position, the primary locking device being embedded and trapped on the female plug in a sliding manner transversely to the axial direction, the primary locking device being provided in the form of a plate arranged transversely to the axial direction, with a manipulating portion arranged perpendicular to said plate, the plate comprising a substantially circular central hole of a slightly larger diameter than the diameter of the male plug, at least one projection or rim being provided in a lower portion of the hole and intended to be received in an annular groove of the male plug, the projection or rim bearing against a shoulder formed on the male plug, which ensures a retraction-preventing locking function, - a movable secondary lock having an active position adapted to prevent the primary locking device from being moved from its locked position, the secondary lock being a separate part able to be interposed, in its active position, in a manner that prevents movement of the primary locking device, the secondary lock being configured to be irreversibly clipped into place in its active position, whereby the fluid connection device establishes a permanent, non-separable connection of the first and second conduits, for ensuring that the chain of sterility remains intact,