Abstract: A new way to make wavelength-division multiplexer using the volume holography technology is proposed to expand the communication capacity of the fiber and separate the light of multi-wavelengths effectively. The properties of wavelength-division demultiplexer were investigated. The holographic gratings were superimposed in 10×10×10 mm3 double-doped LiNbO3 crystals (mixing into Fe and Zn) to separate the multi-wavelengths light transmitting in the same direction. Some theoretical and experimental results on the properties of wavelength-division demultiplexer in double-doped LiNbO3 crystals were given. The experiment result proves that this method is feasible. The multi-channel wavelength-division demultiplexing was realized.