Optical fiber sensing system depends closely on the quality of the laser source, because laser parameters, such as the power stability, linewidth and phase noise, have a great impact on the performance of the fiber sensing system in such parameters as the maximum measuring distance, precision, sensitivity and noise characteristics. Therefore, the related high quality laser source has caused much attention these years. In this article, a brief review on the development of the laser source for fiber sensing is presented. Laser applications in optical fiber sensing are emphasized with the utilization of the narrow-linewidth laser, tunable laser and broadband light source. Finally, the main limiting factors and kernel technology of laser source for the optical fiber sensing are summarized. In order to achieve high performance of optical fiber sensing, the availability of the ideal ultra-narrow-linewidth and ultra-stable laser, which could be tuned at a desired wavelength span and tuning rate, will be definitely one of the main research directions of the future optical fiber sensing.