A slide rail mechanism includes a first slide rail assembly, a second slide rail assembly and a supporting assembly. Each of the slide rail assemblies includes a first rail, a second rail and a third rail movably mounted between the first rail and the second rail. The second rail is longitudinally movable relative to the first rail. The second rail of the first slide rail assembly and the second rail of the second slide rail assembly are respectively arranged with a first mounting device and a second mounting device. The supporting assembly includes a supporting member, and a first connecting device and a second connecting device arranged on the supporting member. The first connecting device and the second connecting device are respectively connected to the first mounting device and the second mounting device.