A dual-wavelength distributed feedback (DFB) fiber laser based on phase sampling is proposed and demonstrated. Change of phase and sampling period is introduced at different positions along a sampling Bragg grating. It is demonstrated theoretically that this structure can provide separate resonant cavities to overcome mode competition caused by gain homogeneous broading. A 0.46 nm-spaced dual-wavelength DFB fiber laser is achieved on an Er-doped fiber with excimer laser and homogeneous phase plate. Experiments shows that dual-wavelength lasing is achieved and laser power is in reverse proportion with coupling coefficient of the FBG.