Thermal radiation high temperature optical fiber sensor is a device sensing temperature based on the phenomenon of blackbody radiation generated by the hotspot in the core of optical fiber. The material of sensing head is the key to the sensor. Three kinds of materials for sensing head are presented via theoretical analysis for principle of thermal radiation temperature measurement, illustration of the working principle of high temperature optical fiber sensor and the characteristics of materials of sensing head. The structures and performance of these materials are further researched, particularly for the material of zirconia crystal sensing head for superhigh temperature detecting.