Abstract: The application principle of the dualspeed motor was introduced. Based on this, the necessity of motor reformation was expounded. The reformation result was compared, and the result shows that the reformation of the dualspeed motor for water circulating pump has features of small investment and quick returns, and can realize the purposes of water regulation，energy conservation and lower consumption.

Key words: waster circulating pump, dual-speed motor, application principle, energy-saving reformation