It discusses the measurement principle and the system design of 3D non-destructive measurement method for the homogeneous entity. The measurement project and its operating process is discussed. The basic operation principle and components of this measurement device are pointed out. It included the digitized minute entity cells and the delaminated measuring method for product profiles based on liquid. It is based on Archimedes' principle and lever principle and gravity moment, combined the equations of the gravity moment and the equations of the center of gravity, the 3D coordinate values of every minute entity cell in different layers can be reckon by computer. By inputting the 3D coordinate values of the product into the related CAD software system, the 3D model could be obtained. The principles, the system software were introduced in details about the measurement system of the homogeneous entity profiles. Proved through principium experiment, the system satisfies the request of the measuring precision. The measurement system is effective and feasible.