Fiber-optic temperature sensor based on thermo-chromic materials is a kind of effective facility to solve the problem of measuring temperature in the electrical power system. But the measuring range by this method is narrow, it is necessary to improve the measuring range by the means of append an attenuator. In this paper,based on traditional fiber optic temperature sensor , the purpose and principle of thermo-chromic optical fiber temperature sensing probe is introduced. The degree of attenuation of temperature which is obtained through ANSYS software thermal simulation is used as an evaluation index to make the choice of probe structure, and analyzes the result of simulation in detail. Finally, the functional between the temperature of heat source and the temperature of attenuator is fitted. So, this paper could be a reference or an example for the application of fiber-optic temperature sensor based on thermo-chromic materials.