1. A three-dimensional data processing and recognizing method, the method comprising: scanning and re-constructing an object to be detected so as to obtain three-dimensional data for recognition of the object to be detected; extracting data matching to features from the three-dimensional data, so that the extracted data constitutes an interested target; with respect to the data matching to features, merging and classifying adjacent data points as one group, to form an image of the merged interested target; recognizing a cross section of the interested target; cutting the interested target by a perpendicular plane which passes through a central point of the cross section and is perpendicular to the cross section, in order to obtain a graph; and recognizing shape of the interested target based on a property of the graph.