1. A system for reproducing an object in a 3D scene, comprising: an object acquiring unit configured to simultaneously acquire at least two channels of video stream data in real time at different angles for an object to be displayed; an object recognizing unit configured to recognize a shape of the object varying in real time from the at least two channels of video stream data; an object tracking unit configured to obtain corresponding object motion trajectory according to the shape of the object varying in real time; and an object projecting unit configured to process the shape of the object varying in real time and the corresponding object motion trajectory into a 3D image and superposition-project the 3D image into the 3D scene in real time; wherein the object tracking unit comprises: a position information obtaining module configured to obtain relative spatial position information of the shape of the object varying in real time; a contact information obtaining module configured to obtain variation information of a determined contact on the shape of the object varying in real time, according to the contact on the shape of the object varying in real time, wherein the contact is a characteristic key point for identifying the object; and a motion trajectory obtaining module configured to obtain corresponding object motion trajectory from a preset motion trajectory database, according to the relative spatial position information and the variation information of the contact.