A novel dual-wavelength (DW) sampled fiber Bragg grating (FBG) is proposed. Phase shift between two adjacent FBG units is achieved by increasing direct current (DC) refractive index of FBG. The FBG with only identical ±1 order reflective spectrum is optimized with cosine sampling function. This method has the advantages of flexible wavelength design, low fabrication precision and low cost. Comparison between uniform DC phase shift FBG, sample DC phase shift FBG and traditional discrete phase shift FBG is made. Uniform DC phase shift FBG and sample DC phase shift FBG are fabricated, which show a good agreement with theory. DW filter with channel spacing 0.08 nm is fabricated, and the experiment results verify the feasibility of this proposed method.