An extraction method based on voxel connectivity and region growth is proposed for the extrusion features of range images.A voxel model of range image data is established with linear octree codes,and a fast transforming algorithm from octree codes to grid codes is introduced to improve the efficiency of searching voxel neighbors,thereby the computing time has been reduced by 50%.Then,the region growth is carried out based on the connectivity of the seed voxel in a specific direction,and a threshold is used to judge the growth result to extract the extrusion feature data.Finally,the method is applied to the liquid cabin range image data of an actual ship and the results of the extraction and threshold option show that the extracting accuracy reaches about 90% when setting the comparison precision as 10－4 mm.The experimental results support a conclution that the method can be used in a point-cloud cutting method to reconstruct the extrusion features.