A novel method for generating highly extinctive optical pulse was proposed. The continuouswave (CW) light is modl山ted by an electrooptic phase modulator, and then modulated by a Mach-Zehnder intensity modulator in which the undesirable chirp components are sufficiently restrained. The modulated light is compressed into pulses by an equivalent chirped 且ber Bragg grating (ECFBG). The theory analysis and simulation showed that the pedestal and wings can be diminished e伍ciently in this way, and ultra-short optical pulse with extinction ratio larger than 30 dB can be generated. The experiment based on ECFBG of which gro叩delay dispersion is -380 ps/nm was demonstrated, it shows that highly extinctive optical pulse shorter than 18 ps at repetition rate of 2.5 GHz can be got when the phase modulation index is 9.