One of the best methods to investigate and calculate a desired quantity using available limited data is the Bayesian statistical method, which has been recently entered the field of nuclear astrophysics and can be used to evaluate the astrophysical S-factors, the cross sections and, as a result, the nuclear reaction rates of Big Bang Nucleosynthesis. This study tries to calculate the astrophysical S-factor and the rate of reaction T(d,n)4He as an important astrophysical reaction with the help of this method in energies lower that electron repulsive barrier, and for this purpose, it uses the R-Software, which leads to improved results in comparison with the non-Bayesian methods for the mentioned reaction rate.