Among the established techniques for measuring fluorescence decay rate

time-correlated single-photon counting(TCSPC)provides unusually high sensitivity

and is

widely used.Sample's decay curves measured by the TCSPC system contain the system's respond function.In order to get the real decay curve of the sample

we have to do the deconvolution.For that

we need a method to do the nonlinear fitting.By now those established nonlinear fitting method have the problem that resolution is sense to the given initial value

and need too much time to do the calculation.To overcome those disadvantages

we build up a new method to do the fitting.The method is based on the practical pace-accelerated means.It has nice precision and good repetition.For a common value

it can easily work out a fairly good resolution.Using this program

we analyzed some sample's decay curve.The result shows that the new method is useful for the fitting to the fluorescence decay curves.