Utilizing the modulation of the refrac tive index of the fiber Bragg grating based on the arc discharge process,a schem e of the single frequency narrow linewidth distributed feedback (DFB) fiber lase r based on the corrugation-pitch-modulated fiber Bragg grating (CPM-FBG) is proposed.The m athematical model and simulation study of the CPM-FBG is established,and the interest of phase shifte d fiber Bragg grating (PSFBG) is proved. An on-line CPM-FBG production system is achieved,and the erbium-doped CPM-FB G is formed.A single- frequency narrow linewidth distributed feedback (DFB) fiber laser is realized, and the laser threshold power is 25.4mW with 3dB linewidth at 805Hz and side mode rejection ratio greater than 48.8dB.