A new elastic support based on the lumped compliance of flexure hinges was presented for a two-axis Fast Steering Mirror(FSM) system,and the methods to analyze the static and dynamic performance of the elastic support were researched. Firstly,the principle of two-axis FSM and the performance demand of an elastic support were analyzed,and the advantages and disadvantages of several existing elastic supports were researched.Then, a new elastic support based on a right-corner flexure hinge structure was put forward and the static and dynamic performance of the new elastic support was studied in detail. By taking a designed two-axis FSM with the performance in Φ90 mm beam aperture, ±2 mrad deflection angle and 300 Hz closed-loop bandwidth for an example, the characteristics of the elastic support were analyzed and the rotational stiffness of the elastic support was measured based on the dSPACE simulation system. Experimental results indicate that the elastic support can meet the performance of FSM well, and its first-order resonance frequency is 78 Hz, and the close-loop bandwidth tested is 340 Hz. It is concluded that the two-axis elastic support based on the lumped compliance of flexure hinge structure can be used for the FSM which needs several mrad deflection angles and several hundred Hz close-loop bandwidths,and it has advanteges in easy machining and a stable rotation center.