Device and method for monitoring three-dimensional stress field of cubic rock sample based on distributed optical fibers

The invention discloses a device and a method for monitoring a three-dimensional stress field of a cubic rock sample based on distributed optical fibers. The distributed optical fiber sensing optical cables are arranged on six vertical surfaces of a rock sample to be measured, and are arranged in a regular rectangular grid according to the minimum bending radius of the distributed optical fiber sensing optical cables; monitoring the strain data of the surface of the rock sample to be measured through the distributed optical fiber sensing optical cable, processing the strain data of the rock sample to be measured through the distributed optical fiber strain demodulator, and sending the processed strain data to the optical fiber data acquisition and processing software and the computer; calculating according to the strain data, performing subdivision data grid processing on each facade, and performing interpolation inversion and three-dimensional stress field visualization on discrete data of a regular rectangu