A tunable cylindrical liquid lens array for two dimensional (2D)/three dimensional (3D) switchable display is proposed. It mainly contains two transparent liquids of different refractive index: liquid 1 and liquid 2. Liquid 1 and liquid 2 are divided by a transparent elastic membrane. The elastic membrane is supported by a micro-clapboard array. Driving these two liquids to flow and the support of micro-clapboard array can change the shape of the elastic membrane, then, the membrane has two shapes as flat shape and tunable cylindrical shape. The focal length of tunable cylindrical liquid lens array extensively adaptive from infinity to a certain positive value is realized. A tunable cylindrical liquid lens array prototype for 2D/3D switchable display is developed. The experimental result proves the prototype′ s tunable focus length ability. The prototype with a matched flat display panel realizes autostereoscopic 3D display, moreover, the elastic membrane can change to flat for regular 2D display. Therefore, 2D/3D switchable display is realized.