The invention relates to a roof
surface layer slope finding method based on parameterization means, and the method is characterized in that the method comprises the steps: S1, obtaining the geometric information of a roof; s2, combining the outer contour of the house with a roof
water diversion line, and identifying a polygon and end points thereof; s3, determining a lifting point on the roof
water diversion line, performing condition screening, determining a
drainage ditch corresponding to the lifting point, obtaining a to-be-lifted height corresponding to the lifting point, and moving the height; s4, constructing a three-dimensional slope surface according to the moved roof
water diversion line and the end points in the polygon where the original roof water diversion line is located, and digging out a
drainage ditch entity from the roof to obtain a roof geometry; and S5, selecting a section,
cutting the roof geometry and the
drainage ditch entity, and outputting a polyline
list of the roof
surface layer and the drainage
ditch detail. Compared with the prior art, the method has the advantages of reducing identification errors of the lifting point and the distance in a more complex roof environment and the like.