The present disclosure relates to a liquid crystal lens, a 3D display panel and methods for controlling the same. A liquid crystal lens for a 3D display panel, including a first substrate, a second substrate, a plurality of first electrodes arranged on the first substrate, a second electrode arranged on the second substrate, a liquid crystal layer arranged between the first substrate and the second substrate, and a control unit. The control unit is configured to control a voltage of the first electrode and of the second electrode so that liquid crystal molecules in the liquid crystal layer deflect to form a plurality of lens equivalent units, and the control unit is further configured to adjust the voltage of the first electrode to change a position of each of the lens equivalent units.