This paper presents an all-fiber， passively Q-switched pulsed laser system with enhanced laser damage threshold and high-power output. A 1060-XP single-mode fiber serves as the scattering medium， utilizing Rayleigh scattering （RS） and stimulated Brillouin scattering （SBS） effects. A fiber Bragg grating with a central wavelength of 1 064 nm and 10% reflectivity forms the resonant cavity mirror. The system produces a bidirectional， tunable laser output with stable Q-switching characteristics under varying pump power. The transition of the laser output through Amplified Spontaneous Emission （ASE）， random lasing， and Q-switched pulsed operation is analyzed. At a pump power of 48.15 W， the system achieves a near-infrared supercontinuum output with a 7-ns pulse width， single-end output power of 11.79 W， wavelength coverage of 1 030-1 650 nm， 23.2% slope efficiency， and a peak power of up to 17 kW. The repetition rate is tunable from 3.7 to 100 kHz. This compact， robust laser design eliminates fragile components， offering a fully integrated， miniaturized solution for pulsed fiber lasers.