Square plate chain pump, about the North and South Dynasties, is the originator of the modern pump. Square chain pump is one of the most widely used mechanical invention, first appeared in China. It can be hand-pulled, pedal, cattle and water transfer and other power-driven. Car body as a water wooden groove, mounted on both ends of the wooden wheel shaft. By a series of parallel to the composition of wood plate chain (referred to as road board) placed in the tank, and bypass the car at both ends of the wheel plate (known as keel leaf), the road board and the keel leaf meshing. On both ends of the upper axle equipped with four Shui Mu, step moving timbers, the last round of operation, thereby driving the keel plate rotation, road plank wiper ashore in the wood. According to the sealing performance of the square board, the pump can lift the water is not the same height.