Abstract: In the nuclear waste processing, reduction of highly toxic and mobility radioactive U(Ⅵ) to low toxicity and mobility radioactive nuclide uranium U(Ⅵ) is proposed as a very critical process step to remediate U-contaminated. Zero-valent iron (ZVI) reduction technology show a good application prospect for reduction of radioactive nuclide uranium U(Ⅵ) because of its low apparatus cost, environmentally friendly and easy operation, ect. This paper is written for discussing the three kinds of interface chemical mechanism between U(Ⅵ) and zero-valent iron in detail: reduction precipitation mechanism, adsorption mechanism and coprecipitation mechanism. In addition, the water chemistry factors on this mechanism such as redox conditions, medium pH, co-existent ions, natural organic matter and microorganism are deeply analyzed, and the further research on how to effectively and deeply carry out the research on the remediation of U(Ⅵ) by zero-valent iron is also discussed.