With the string melting version of a multiphase transport(AMPT) model, we analyze the transverse momentum dependence of HBT radius $R_{rm s}$ and the single-pion transverse angle distribution in central Au+Au collisions at $sqrt{S_{NN}}=19.6, 27, 39, 62.4, 200$ GeV. And base on a series of functions, a numerical connection between these two phenomena has been built. We can estimate the single-pion transverse angle distribution from the HBT analysis.