This paper reports the observed changes for equilibrium factors between ²²⁶Ra and ²²²Rn with sealing time of the samples. The samples include soil, raw coal, mineral water, cement, rock, etc. Especially the conceptions of "pre-equilibrium time" and "pre-equilibrium factor" have been put forward and methods of measuring and processing data have been given which can be used for rapidly reporting activity of ²²⁶Ra in samples with unknown equilibrium factor. It is definitely concluded that, using methods given in the paper, a test report will be completed in 3~7 days, instead of one month, after receiving the sample whose activity is not lower than LLD of the spectrometer.