1. A computer-based method for aligning point clouds, the method comprising: (a) inputting data comprising a point cloud data of a reference object and a point cloud data of a to-be-measured object, wherein the point cloud data of the reference object and the point cloud data of the to-be-measured object corresponds to a point cloud of the reference object and to a point cloud of the to-be-measured object respectively; (b) confirming an original position of the point cloud of the to-be-measured object, according to the point cloud data of the reference object and the point cloud data of the to-be-measured object, comprising: determining a cubical figure boxR of the point cloud of the reference object; determining a cubical figure boxM of the point cloud of the to-be-measured object; setting an original position of the point cloud of the to-be-measured object, when boxR and boxM intersect; and determining a center of the point cloud of the reference object, determining a center of the point cloud of the to-be-measured object, and determining an original position of the point cloud of the to-be-measured object according to the center of the point cloud of the reference object and the center of the point cloud of the to-be-measured object upon the condition that the boxR and the boxM do not intersect; (c) determining, by using iteration, a virtual position of the point cloud of the to-be-measured object at each iteration according to the original position; (d) determining a minimum distance between the point cloud of the reference object and the point cloud of the to-be-measured object according to the virtual position of the point cloud of the to-be-measured object at a last iteration of step (c), and determining coordinates of each point in the point cloud of the to-be-measured object corresponding to the minimum distance; and (e) moving each point in the point cloud of the to-be-measured object according to the coordinates of a corresponding point calculated in step (d), so as to align the point cloud of the reference object and the point cloud of the to-be-measured object.