According to the different movement characters of screw segment and centrifugal segment of liquid-solid two-phase flow in the screw centrifugal impeller and the structure characters of screw centrifugal pump impeller, the vane profile parameter equation group for variable-dip screw centrifugal pump was derived. The meridian velocity distribution can be changed though changing some parameters of the vane profile parameter equation group. Thus the better meridian velocity distribution could be found by using this method. Using the parameter equation group, the CAD and numerical simulation of 3-D flow field were also facilitated for screw centrifugal pump.