Generally, the theoretical analysis of the fluorescent life time temperature measurement is based on the assumption of
the exponential life time characteristic, but in practice, the actual curve of the fluorescence are different from exponential.
This is the key-influence on the stability of the high precision fluorescent measurement system. The differences are
analyzed base on the theoretical mechanism of fluorescent, and a cutting and normalized method is given to describe the
degree of the non-exponent of the actual fluorescent curve defer from the exponential curve. Several kinds of typical
fluorescence materials spectrum and its cutting and normalized experiment results verify this theoretical analysis. Some
effective measures to improve the non-exponent of the system are taken and are applied to a temperature measurement
system based on actual fluorescent curve analysis with resolution 0.1°C, precisions ±0.2°C, and real-time calibration is
carried on. Based the theory base and the actuality of fluorescence optical fiber temperature sensor, two methods about
fluorescence decay time constant are proposed. In the mean time, the mathematic model has been formed and analysis,
so that the different schemes are selected in different situation.