The invention discloses a tight tube optical fiber grating serial sensing optical cable which comprises a sensing optical fiber and a tightly-coated sheath with the external diameter of 900 mu m; the external diameter of the sensing optical fiber is same as the internal diameter of the tightly-coated sheath; the sensing optical fiber is centrally coated by the tightly-coated sheath and tightly coated and touched with the tight tube sheath; optical fiber Bragg gratings with different parameters and intervals are written on the sensing optical fiber according to needs and are externally provided with coating protection. The tight coating of the tight tube optical fiber grating serial sensing optical cable has certain tensile strength and folding strength, can be used for better protecting the central sensing optical fiber and the optical fiber gratings, and reducing and even eliminating chirp phenomena occurring in the installation processes such as sticking; and by virtue of the special encapsulation protection of the tight coating, the survival rate and sensitivity of an optical fiber sensor in the engineering detection field can be greatly improved.