In this work, the assembly structure of ZnO nanorods was successfully prepared by microwave heating method using small nanoparticles of Zn-Al hydrotalcite as seeds. The morphology of this assembly structure was obviously affected by the amount of seed liquid and microwave heating power. Not affected by the reaction time. It was found that when using a lower seed liquid amount (5 to 10 mL) and a low microwave heating power (300 W), it is advantageous to prepare a flower cluster assembly structure of ZnO nanorods; the length of ZnO nanorods in this structure Between a few hundred nanometers and 2 meters, the diameter is between 100 nm and 300 nm. When a large amount of seed liquid (20 to 50 mL) and high microwave heating power (700 W) are used, it is easy to obtain an assembly structure of two kinds of epitaxial ZnO nanorods or nanotubes of hydrotalcite-like nanosheets with a diameter of about 5 m. The assembled structure of this ZnO nanorod will have broad application prospects in photocatalysis, solar cells and wastewater treatment.