An integrated 4×4 planar electrooptic switch is designed based on the electrooptic effect in ferroelectric inverted domains. It integrated four minute halfparabola shaped and four parabola shaped deflectors with the same configurations in a ferroelectric wafer. To optimize the design of the parabola shaped deflectors, an appropriate electrooptic switch is provided. Its properties of switch and exchange are analyzed using the beam propagation method (BPM). Simulation results show that the 4×4 planar electrooptic switch is feasible and the beam deflection errors can be compensated in practice by adjusting applied electricfield. The size of the optical switch is 48 mm×2.2 mm×0.5 mm and its maximum applied electricfield is about 13.73 V/μm. It has potential applications in highspeed optical exchange systems.