According to transverse profile equation of twin-screw pump’s screw armature, the basic milling cutter blade profile equation was established. By using Matlab software, the nonlinear equation, such as trigonometric functions in the processing of design the cutter were solved, and a series of effective discrete profile points’ data were gotten. For process of solving milling cutter profile, it is studied that the separation phenomenon of the cutter blade appeared as a result of the workpiece with sharp point profile, so as to solve the cutter blade profile exactly.