Hybrid wood materials have attracted considerable attention because they have combined advantages of both wood and inorganic compounds. This work investigated the microstructural morphology, thermal stability, ultraviolet (UV) stability, and antibacterial property of composites made from wood/ZnO hybrid materials through a facile in-situ chemosynthesis methods. The X-ray diffraction (XRD) and thermogravimetric analysis (TGA) results indicated that the synthesized ZnO particles had an average grain size of about 10.8 nm. The scanning electron microscopy (SEM) observations showed that ZnO nanoflowers self-assembled with nanosheets were presented in wood cell lumens and increased with increasing Zn2+ concentrations. ZnO nanoparticles were also generated in the wood cell wall, which was confirmed by the results of energy-dispersive spectroscopy (EDS). The TGA tests also indicated that the thermal stability of wood/ZnO hybrid materials was improved after the formation of ZnO inorganic particles. Finally, the results of antibacterial efficacy tests and UV resistance tests revealed that ZnO nanoparticles showed a promising future as antimicrobial agents against Escherichia coli (E. coli) and UV resistance agents for wood protection.