The invention provides a mode-locked 
fiber laser and a pulse 
laser generation method, and belongs to the field of a 
fiber laser. The mode-locked 
fiber laser comprises a pumped source and a mode-locked laser 
resonator, and the mode-locked laser 
resonator comprises a reflection part, a 
gain fiber, a polarization-maintaining filter and a 
saturable absorption mirror which are successively coupled, wherein the 
saturable absorption mirror is used for 
mode locking. Pump light emitted by the pumped source penetrates into the 
gain fiber to generate 
signal light, the 
signal light penetrates into the 
saturable absorption mirror after being processed into 
signal light in a preset polarization direction and within a preset 
wavelength scope by the polarization-maintaining filter and returns to the polarization-maintaining filter after 
mode locking of the saturable absorption mirror, the 
signal light returning to the polarization-maintaining filter re-penetrates into the 
gain fiber and is input to the reflection part after being amplified by the gain fiber, and the portion, which meets the transmission condition of the reflection part, in the 
signal light amplified by the gain fiber is output. Compared to a conventional mode-locked 
fiber laser, the mode-locked 
fiber laser provided by the invention is simple in structure and high in stability and reliability, thereby facilitating 
engineering application.