Abstract: To reduce the negative effect of algae on conventional water treatment, the nanocatalytic-electroflotation process was used to treat the lake water. The results indicated that, nanocatalytic-electroflotation process was a widely used technique to kill algae. Treated by nanocatalytic-electroflotation process, the concentration removal rate of Cyanobacteria, which was the dominant algae in the lake water, was as high as 99.1%. The effects of current density, residence time and electrode gap on algae removal efficiency were investigated by means of orthogonal test. The results showed that the sequences of influential factors which affected the algae removal efficiency were as follows:current density > residence time > electrode gap. Considering the comprehensive economic, the optimum process conditions were that current density was 5 mA/cm², the residence time of 6 minutes, and electrode gap was 10 mm.