We have successfully developed an 8 channels time division sub-carrier semiconductor DFB laser wavelength locker. We use 1 kHz sinusoidal time division electric signal and 1% AM degree to modulate every 1.55μm waveband DFB laser respectively. 2% optic signal of each DFB laser is divided into two parts, one part passing through a F-P etalon whose free spectral range is 100 GHz and another as reference signal. Optic electric differential signal of two paths feedback controls DFB lasers' temperature in order to make each DFB laser lock at the wavelength they are needed respectively. Test results show that the laser frequency spacing of wavelength-lock is 100 GHz and wavelength-lock accuracy is better than±2.5 GHz. This method can also be used in 50 GHz frequency spacing and more channels of multi-wavelength locker. This paper mainly introduces the optic and electric process and control method of the locker.