<p>Cerium dioxide (CeO₂) has abundant intrinsic oxygen vacancies (OVs), and magnesium–aluminum hydrotalcite (MgAl-LDH) with abundant negative charges between the layers has a large specific surface area and rich mesoporous structure. Therefore, both materials are often used to degrade antibiotics existing in water in the form of amphoteric molecules. However, CeO₂ has a high carrier recombination rate, and MgAl-LDH has weak absorption capacity for visible light. To overcome the shortcomings of these two materials, they were combined by hydrothermal method, and MgAl-LDH grew in situ on needle-like CeO₂. The composite material MgAl-LDH/CeO₂ exhibits a significantly increased specific surface area, further optimized mesoporous structure, and a substantial enhancement in adsorption capacity while exposing a large number of active sites. A Z-scheme heterostructure was formed between the composite material MgAl-LDH/CeO₂, effectively solving the problem of the high carrier recombination rate of CeO₂. The intrinsic OVs possessed by CeO₂ and the OVs formed at the interface between the two due to atomic substitution and doping also play a significant role in catalytic degradation. Therefore, the TC removal rate of the composite material MgAl-LDH/CeO₂-2 reached 92.4%, which was 1.5 times that of CeO₂ and MgAl-LDH. After 5 cycles, the removal rate could still reach 84.1%. The toxicity of the products of TC after degradation by the composite material MgAl-LDH/CeO₂ was significantly reduced after toxicity testing.</p>