A spiral-flow type defoaming device is characterized by comprising a spiral-flow guide defoaming body. A flow inlet for tangentially guiding flow into the spiral-flow guide defoaming body is arranged outside the spiral-flow guide defoaming body, a foam collector is arranged in the spiral-flow guide defoaming body, and a power-driven brush defoamer is assembled on the foam collector. The spiral-flow type defoaming device is reasonable in structural design and obvious in defoaming effect and drives foam to be collected in the foam collector by spiral-flow centrifugal force for guiding water with foam in the spiral-flow guide defoaming body, and mechanically driven brush defoaming agents can perform low-cost efficient defoaming operation. The spiral-flow type defoaming device is simple in structure and low in operating cost and can be widely applied to defoaming operation for refrigerating cycle by surface water in a power plant.