Abstract: Low flow,high speed centrifugal pump can be used in kinds of equipment of aeronautics,astronautics,power engineering and computing techniques.It always has small size and low specific speed.But the existing theory mostly is based on the empirical designs of medium and high specific speed pumps.When used in low flow,high speed pumps,good results cannot be obtained.In this paper,a performance prediction model of low flow,high speed centrifugal pump is presented.The influence of disk diameter and auxiliary system exit pressure on system efficiency is analyzed.An optimum design method using them as design parameters and system efficiency as object is established.On the basis of this method,an example is calculated to prove that the method is feasible and effective.