The outer sheath of the tight-fitting single-core strain optical cable is made of polymer. The sensing optical fiber is closely connected with the outer sheath. The external strain can be transmitted to the internal sensing optical fiber through the protective sheath. It has good flexibility. In terms of layout, the mechanical strength is general, and it can withstand low intensity external impact. It can be used with the distributed Brillouin optical fiber sensing demodulator to measure the strain distribution along the optical fiber, It is applicable to indoor environment or outdoor environment monitoring with low external impact risk.