Abstract: Metal organic frameworks (MOFs) have shown broad application prospects in the field of photocatalysis due to their high specific surface area, structural diversity, and functional tunability. However, the high recombination rate of photo-generated charge carriers and insufficient stability limit their practical applications. The composite modification of MOFs with semiconductor materials is an effective strategy to enhance photocatalytic efficiency. In this study, MOF-based heterojunction Tb-ZnO/MIL-101(Fe) composites with different molar ratios were prepared by a one-step solvothermal method, where heterojunction interfaces were constructed to regulate the separation behavior of photoinduced charge carriers. Multiple characterization techniques were employed to analyze the phase and microstructure, optical, and electrical properties of the samples. Using Rhodamine B (RhB) as the target pollutant, the influence of the molar ratio on the photocatalytic performance was comprehensively evaluated. The experimental results indicated that when the molar ratio of Tb-ZnO/MIL-101(Fe) is 4∶1, the degradation efficiency of RhB reaches 100% within 50 min, which is 7.45 times and 4.55 times higher than that of single Tb-ZnO and MIL-101(Fe), respectively. In addition, the composite material also exhibits excellent degradation performance towards phenol red (PR), methylene blue (MB), and methyl orange (MO). Mechanism studies reveal that the Z-scheme heterojunction formed between MIL-101(Fe) and Tb-ZnO significantly promotes the spatial separation of photoinduced charge carriers while enhancing visible light absorption through synergistic effects. This work provides a novel and effective approach for constructing advanced visible-light-driven photocatalysts.