The invention belongs to the field of optical fiber time domain reflection measurement, in particular to a high-spatial-resolution OTDR device and method based on a high-speed complementary Gray code, the high-speed complementary Gray code is used as a modulation signal, and a distributed feedback laser is directly modulated through a driving circuit to output broadband, stable and non-obvious-periodicity chaotic laser to serve as detection light, so that high-precision diagnosis of optical fiber faults is realized; a low-speed analog-to-digital converter is used for reducing the ADC rate and achieving a good detection effect, and a rapid Hadamard conversion module is used for rapidly calculating cross correlation; the designed chaotic OTDR is simple in structure, stable in performance and low in cost, integration and productization can be achieved easily, and the requirements in practical engineering application can be met.
High-spatial-resolution OTDR device and method based on high-speed complementary Gray code