A multi-stage hinge assembly has a first connecting board, a second connecting board, a first hinge, a second hinge, an inner mounting lever and an outer mounting lever. The first connecting board has a first ring, a second ring and a recess. The second connecting board has a first ring and a second ring. The first hinge is mounted on the connecting boards. The second hinge is mounted on the connecting boards. The inner mounting lever is mounted pivotally on the second mounting bracket of the first hinge and the rotating head of the second hinge and has two retaining plates, a holding frame and a spring. The outer mounting lever is mounted pivotally on the second mounting bracket of the first hinge and the rotating head of the second hinge.