In the ultracold atomic system, to observe the Parity-Time (PT) symmetry with the gain balance requires controlled gain/loss of atom population and coherent coupling. We present a proposal to obtain an exponential growth of the atom population by dynamically controlling atom transport in a double-well trap on an atom chip. We numerically investigate the transport dynamics of the atomic ensemble between the sub-wells by using the direct simulation Monte Carlo method. It is found that the initial number and temperature of the atom cloud remarkably affect the transport performance, such as gain rate and transfer efficiency of the atom population in the target trap. Moreover, the effect of the lifting time of the left-well on the growing trend of the atom population in the right-well is analyzed in detail. Our strategy provides an achievable way for realizing a PT symmetric quantum system with gain/loss in ultracold atomic gas.