The proper lift pump for deepsea mining is one of key equipment of hydraulic mining system of ocean polymetallic nodules. The requirements for this pump are as follows: resistance to high pressure, wear and corrosion, high efficiency, good rdliability and long lift. Therefore, it is very difficult for us to develop this pump.The authors describe tile present situation of using it in other countries, point out the basic factors and criteria that should be considered in the design, and put forward the conception of proper multistage centrifugal lift pump for deepsea mining.