The new modified Debye-Hückel electron shielding potential, which has been used in the study of fusion cross sections in plasma, is adopted in the atomic structure calculation under plasma environment. By variation of the Tsallis entropic parameter q, the average effect of plasma environment fluctuation is considered in atomic structure of plasma. A calculation using such modified Debye-Hückel potential of the He-like Al shows that the free electron distribution is different between the modified Debye-Hückel model and the linear Debye-Hückel model. This statistic method by considering the plasma fluctuation can also be extended to other plasma screening model, such as the self-consistent ion sphere model.