The Al doped ZnO nanosheet arrays with high surface area and high energy surface exposure had been prepared by hydrothermal methods assisted with pulsed electromagnetic field (PEMF). The properties of Al doped ZnO nanosheet arrays were studied by FESEM, XRD, and XPS. The results showed that the ZnO nanostructure was transformed from the rodlike to the hexagonal flake after Al doping. When the Mole fraction of Al was 1%, the ZnO nanosheets was interlaced with each other regularly and grown on the substrate. Comparing with the conventional nanorod, the ZnO nanosheets have greater surface area and higher energy surface exposure. Furthermore, the formation mechanism of nanosheet was analyzed and discussed in detail.