Abstract: A new hydraulic design method of single channel impeller was discussed in this paper, it is simpler than the former design method of single channel impeller. The new method is especially fit for program CAD software. Based on summing up many excellent hydraulic models of single channel impeller, it gave all kinds of coefficient values of axial section. With reference to the design method of plan hydraulic design of double channel impeller, the new design method of plan hydraulic of single channel impeller is put forward. It introduced a new change rule of section area and an equation of plan channel midline. At last, a programming method and an example of design were given.