In order to reveal the performance of the ultra-filtration adopted in the radioactive wastewater treatment,experiments were carried out on a pilot UF equipment using the wastewater containing the simulated nuclides.Results showed that the nuclides could be rejected by UF efficiently and the rejection ratio is influenced by pH,with different effects on the rejection of Fe
3+,Co
2+,Mn
2+ and Ni
2+.Theoretical calculation was performed to explain the phenomenon and rejection mechanism was interpreted.