Disclosed are a pulse laser generator and an optical fiber sensor system using the same. The optical fiber sensor system includes a main optical coupler that receives pulse laser light generated from a pulse laser generator from a first input terminal, branches the light to first and second output terminals to output, and outputs, through a third output terminal, light input reversely from the first and second output terminals, a reference optical fiber that is connected to the first output terminal, a multi-point sensing optical fiber unit that is connected to the second output terminal, and in which optical fibers are connected in series or in parallel corresponding to a plurality of sensing points, an optical detection unit that is connected to the third output terminal, and a diagnosis processing unit that detects a change of the physical quantity for the sensing points from signals from the optical detection unit.