The invention provides a system and a method for diagnosing a breaking type of an optical cable based on breakpoint graphic feature points. The system comprises at least one optical cable fault diagnosis terminal, a coupler, and an optical cable; wherein a reflection waveform of the optical cable is acquired in real time through the optical cable fault diagnosis terminal, then a reflection opticalwave graph of a breakpoint is obtained, after that, feature points of the reflection optical wave graph of the breakpoint are compared with feature points of optical wave graphs of breaking types recorded by the optical cable fault diagnosis terminal, so as to determine the breaking type of the optical cable and perform corresponding early warning. The system of the invention adopts a detection light which is orthogonal to a communication signal in wavelength, thus communication of the optical cable can not be affected; at the same time, the system is simple in structure, low in cost, and good in using effect.