The invention provides a novel design method and a fabrication technology for a fiber grating temperature sensitizing sensor. The sensor adopts a bimetal structure, which differs from the method of fiber grating temperature sensitization in the prior bimetal structure. The design uses a small thermal expansion coefficient material as a base instead of a large thermal expansion coefficient material to achieve the purpose of temperature sensitization. The design has two major advantages of that the problem that high resolution temperature sensor can not be preserved and transported in a high temperature is solved; the impact caused by the inertia of the metal on the response speed of the sensor is reduced; and the response speed of the sensor is improved.