Water diversion is not only an effective measure for the redistribution of water resources, but also an effective restoration means of ecology environment. On the basis of evaluation on research result of ecology restoration and environment renovation of water diversion project.This paper reviewed the effects of ecology and environment of water diversion project and its potential impact;it also elucidated the environment improvement mechanism of water diversion project which included dilution role and direct improvement of hydraulic conditions so as to indirectly enhance the self purification of water body.Finally,the current limiting factors for application of water diversion project and problems are limitation of water sources, costs for projects construction and operation, non long-term of water quality improvement,potential increase of pollution loading in lower reaches and unclear inhibition mechanism for algae bloom.