Three-dimensional model rebuilding method of aviation engine blade tip missing parts

The invention discloses a three-dimensional model rebuilding method of aviation engine blade tip missing parts. The three-dimensional model rebuilding method adopts the following process steps: 1) picking out abraded blades appropriate for being repaired in an extension mode and cutting the abraded parts flat; 2) measuring the blades to be repaired with a high-accuracy digitization three-dimensional measurement instrument to acquire three-dimensional point cloud data of the parts to be repaired; then conducting denoising, data compaction and data pre-processing on the point cloud data; 3) rebuilding the abraded blades to be with the rebuilding accuracy >=0.02mm by adopting a non-uniform rational B-spline (NURBS) method; 4) extending curved surfaces and rebuilding a three-dimensional model of missing parts of the abraded blades with rebuilding accuracy+/- 0.02mm; and 5) conducting intersection and cutting a plurality of extended NURBS curved surfaces to acquire the three-dimensional model of the missing parts of the abraded blades. An analytical method, a partition method, a tracking method or an implicit function method is adopted by the algorithm of intersection of the curved surfaces.