In the field of integrated optics, optical wavelength splitters is a key element in light signal redistribution. A optical wavelength splitter was presented for 1.31 μm and 1.55 μm wavelengths with TE mode. The device was based on the operating principle of a directional coupler in two parallel LiNbO3 photonic wire, and can be designed and simulated by finite element method. The calculated steady-state field distributions indicate that the wavelengths of 1.31 μm and 1.55 μm light waves are spatially separated. In this device, transmittances at the 1.31 and 1.55 μm wavelength are 91% and 86% respectively. The size of this device is only 26.2 μm×10.1 μm.