For improving the strain response sensitivity, this article proposes one fiber grating strain sensor based on titanium alloy substrate. The package uses titanium (TC4) as packaging material according to the theory of elastic modulus and uses barbell-like structure according to the transfer principle of mechanics. It obtains the strain response sensitivity and the correlation coefficient of reflection wavelength and strain. Experimental results show that the sensor which adopts this package design can obtain higher strain response sensitivity and better correlation coefficient of reflection wavelength and strain