The invention discloses an intelligent flat encircling type temperature monitoring single-core cable based on an optical fiber grating. Conductors are located at the center of a cable core, the external parts of the conductors are wrapped by an insulating layer, an optical fiber sensing unit comprises a grating optical fiber and a protection tube arranged at the external part of the grating optical fiber in a sleeved manner, the optical fiber sensing unit and a plurality of filling strips are distributed at the external part of the insulating layer in a circumferential manner to form a cable core with a circular cross section, each filling strip is formed by enclosure of an inner wall, an outer wall and two sidewalls, and the sidewalls of each two adjacent filling strips are abutted against each other. According to the intelligent flat encircling type temperature monitoring single-core cable based on the optical fiber grating with an optimized design, the structure and the design are reasonable, the grating optical fiber is arranged in the cable core, the temperature of the cable can be rapidly and accurately monitored through detection of the change of a traveling path of light inthe optical fiber, the filling strips in the cable core are designed in an optimized manner, on one hand, the cable core can be round, and on the other hand, the position of the optical fiber sensingunit is fixed during usage and the movement is avoided.