The invention discloses a method for measuring a geologic age on the basis of a thermoanalysis. The method comprises the following steps: selecting a
reference sample, measuring the average values of <238>U, <232>Th and <147>Sm isotopic contents of the
reference sample, calculating the values of N238, N235, N232 and N147<S>, calculating the standard N4<He> of the
reference sample, making the isothermal DSC curve of the reference sample by a differential scanning
calorimeter, measuring the annealing quality in a
unit mass, calculating the annealing heat released by an average of alpha-
ion nuclear tracks of the reference sample, then measuring the contents of
uranium,
thorium and
samarium in a sample to be measured, calculating N235, N232 and N147<S>, making the isothermal DSC curve of the sample to be measured by using the differential scanning
calorimeter, measuring the annealing heat, calculating the number of the nuclear tracks of the sample to be measured in the
unit mass, and finally calculating the geologic age t of the sample to be measured, wherein the geologic environments experienced by the sample to be measured and the reference sample are similar. According to the method disclosed by the invention, a
helium measurement is replaced by a
heat measurement, and the method is simple and practical.