Turbine blade is the core part of aero-engine. It is necessary to register the measured point cloud with CAD model quickly and accurately for NC machining after precision casting. In view of the problem of the initial posit ion and orientation of the measured point cloud

two kinds of pre-alignment algorithms are introduced and implemented

which are the fast alignment based on principal component analysis and manually associated pre-alignment. As for the low efficiency of searching match point

this paper introduces and implements three searching algorithms

which are grid method

normed space projection method and fast search method based on kd–tree. Through comparative analysis

it is pointed out that the fast search method based on kd–tree has better computational efficiency. On this basis

the registration scheme of manual association pre-alignment

match point search based on kd-tree and ICP method is determined. The difference interval between the measured point cloud and CAD model after registration is [–0.06 mm

+0.1 mm]

which is accord with the turbine blade casting accuracy.