In this study, a composite structure of zinc oxide (ZnO) nanofibers and nanorods was prepared on a silicon substrate by combining electrospinning and hydrothermal methods. ZnO/PVP nanofibers are prepared by electrospinning components containing polyvinylpyrrolidone (PVP), ethanol (Ethanol) and zinc acetate, and then calcined at 500°C for 4 hours. Crystallized ZnO nanofibers are then used as the ZnO seed layer, and ZnO nanorods are grown on the nanofibers by hydrothermal method. Combining these two low-cost processes can prepare a ZnO nanostructure with a high specific surface area, which can improve the sensitivity of ZnO to hydrogen. The ZnO nanostructure was analyzed by electron microscope (SEM), and X-ray diffraction (XRD). The experimental results show that the ZnO/PVP nanofibers obtained by electrospinning for 2 hours have the best crystallinity after being calcined. ZnO nanorods are then hydrothermally grown on the surface of the nanofibers. As a component material for hydrogen sensing, the sensitivity can reach 61.7% at a hydrogen concentration of 4500 ppm.