Laser power sampling method and device

The embodiments of the invention provide a laser power sampling method and device, for solving the technical problem of crash of a whole fiber laser system, caused by damage to fiber cores in a tapering process in the prior art of laser power sampling when a beam splitter is usually taken as a sampling device and employs a tapering mode in most cases to enable a part of signal light in original fiber cores to overflow to sampling fibers for power sampling. According to the laser power sampling method and device provided by the invention, in accordance with the Rayleigh scattering law, diffusion light escaping from transmission fibers is acquired, through obtaining power of the diffusion light, power of transmission laser in the transmission fibers, needing to be measured is accurately obtained, damage to the transmission laser is reduced to a great degree, and the technical effect of lossless laser power sampling to a quite large extent is realized.