The invention belongs to the field of parametric modeling of airplanes, and particularly relates to a geometric profile parametric modeling method of a forefuselage protrusion of an
airplane. The method comprises the following steps: constructing a front
fuselage grid model; acquiring a front section and a rear section of the protrusion arrangement position on the front
fuselage grid model along a predetermined direction; fitting a first sample line according to the geometrical shape of the geometrical projection of the front
fuselage on the front fuselage profile, and obtaining the multipoint coordinates of the first sample line; fitting a second spline line according to the geometric shape of the geometric projection of the protrusion on the front fuselage section, and obtaining the multipoint coordinates of the second spline line; removing an inner point after the first spline line and the second spline line intersect to obtain a third spline line; and determining a front fuselage grid model with a protrusion according to the plurality of third spline lines. According to the method, the corresponding shape of the profile in a specific area can be directly controlled by controlling the
characteristic equation and the corresponding size of the protrusion in the profile, so that the precise control of local geometry is realized.