The invention belongs to the five-axis 
numerical control machine tool 
machining field, and provides a semi-analysis modeling method of a contact area between a ball-
end milling cutter and a guide vane. The semi-analysis modeling method of a contact area between a ball-
end milling cutter and a guide vane includes the following steps: performing cutter path 
programming, and setting 
numerical control machining parameters; establishing a workpiece coordinate 
system, and acquiring the parameter equations of the design surface and the 
machining surface of the vane, and the movement track equation of the ball center of the 
milling cutter; determining the cutter contact point and the 
cutter location point during the 
machining process, taking the cutter contact point and the 
cutter location point as the origin to respectively establish a three dimensional rectangular coordinate 
system; converting solving problems of No.1-No.4 boundary curves of the contact area into 
projection equation solving problems of the curves in an XL-YL two dimensional coordinate 
system, and respectively solving the projection equations of the No.1-No.4 boundary curves; and obtaining the intersection points of the No.1-No.4 boundary curves, by mutually making a simultaneous system of equations, and obtaining the projection of the contact area. The semi-analysis modeling method of a contact area between a ball-
end milling cutter and a guide vane can solve the problem of performing analysis modeling of the contact area during the process of 
processing a straight-vane-body vane molded in a vane grid by means of a ball-end 
milling cutter on a five-axis 
numerical control machine tool.