In order to solve the problem of inspecting the optical fiber defects, a detection method based laser was proposed to inspect the optical fiber defects in this paper. Though analyzing the basic structure of optical fiber defectstheoretically the principle of detection, a kind of experimental device was designed and established, which was used to carry out the detection experiments of the defects. In the experiment, a collimated He-Ne laser beam transverse incident fiber and the distribution image of optical forward scattering pattern on the optical scree were obtained for the next step image processing. Compared to the experimental results of the microscope method, it is found that the laser detection method is more effective to detect the defect of the optical fiber and has the same detection accuracy as the microscope method. The method can be used as a fiber drawing repetition measurement before coating the optical fiber.