In order to obtain L-band Q-switched pulse, this paper designs Q-switched laser based on Propyl alcohol saturable ab-sorber, the saturable absorber is made of organic solution Propyl alcohol, and the modulation depth of the saturable absorber is measured to be 5.58%. The L-band pulse is obtained by applying saturable absorber to Q-switched laser. The average output pow-er of the Q-switched fiber laser is 0.79 mW with the pulse repetition rate of 20.9 kHz and the pulse energy is up to 36.7 nJ when the pump power of the laser is 230 mW.