A multistage pump refers to a pump with two or more impellers, which can absorb and press water in stages and multiple stages, so as to lift the water to a very high position. The lift can be increased or decreased according to the needs of the pump impeller. The multistage pump has the characteristics of high efficiency, wide performance range, safe and stable operation, low noise, long life, convenient installation and maintenance, etc. It is suitable for conveying clean water without solid particles or liquids with physical and chemical properties similar to clean water.