TE mode has larger cord coefficient and reflective index than TM mode in Fabry-Perot laser diode,when they realize injection locking without power less.The signal from TE mode increases,meanwhile,the signal from TM mode decreases.This character makes Fabry-Perot laser diode like a polarizer.Using the principle of injection locking for Fabry-Perot laser diode,we transfered the polarized light into part polarized light,reducing the polarization sensitivity for the transmission signal,improving the quality of the transmission signal.Besides,multi-wavelength injection-locking was demonstrated by using Fabry-Perot laser diode for the first time.