An improved extraction algorithm of boundary characteristic points was proposed, which includes four steps: first, the spacial
index structure of the scattered pointcloudwas constructed based on the R*tree; second, the local model reference data was
obtained based on the structure and the datum plane was set up; third, the maximum distance between the point of reference data
and datum plane was computed, and the distance between the target point and the datum plane was computed; fourth, the data
boundary characteristic was identified by comparing the two distances. The accuracy and rapidity extraction of scatter data
boundary characteristic was proved by application examples.