The invention discloses a cable tunnel drilling influence range measuring method based on BOTDR (Brillouin Optical Time Domain Reflectometer) optical fiber sensor technology. The method includes the steps of forming long drilling hole in the rock by being parallel to a tunnel, and arranging distributed optical fiber in the long-drilling hole; forming different pressure-release drilling holes withdifferent diameters under the long drilling hole provided with the distributed optical fiber; through an optical fiber interrogator, acquiring surrounding rock compatible deformation data caused by pressure-release drilling, and determining the drilling influence range. By the method, drilling influence range can be measured on site accurately, and the gap of measuring drilling interval on site isfilled, danger can be reduced, while work efficiency can be improved, labor cost can be saved, stability of the cable tunnel can be kept, and safety transmission of power of cables can be guaranteed.