A fluid passage connection device includes a positioning mechanism that incorporates a male coupler attached to a stationary base member and a female coupler attached to a movable member, and that positions the movable member with respect to the base member so that it becomes possible to connect the male and female couplers, and a clamping mechanism that drives the movable member in order to clamp and fix the movable member with respect to the base member by the elastic force of a spring, and that also releases this clamping with the hydraulic pressure of a hydraulic cylinder; and the male coupler has a connection sleeve that is driven to retract by hydraulic pressure and is driven to advance by a spring, with a hydraulic passage being provided that interconnects a hydraulic pressure operation chamber of the connection sleeve and an unclamping hydraulic chamber of the hydraulic cylinder.