Applications of Virtual Reality (VR) technology in many fields have gained great success. In the product development field, VR is a good tool to provide interactive and friendly human-machine interface. Freeform Object Design and Simultaneous Manufacturing (FODSM) uses VR to establish an interactive design environment and enable simultaneous manufacturing. It aims at improving design efficiency, creativity, ease of use, and also aims at integrating design and manufacturing in order to obtain the designed object by the designer independently and simultaneously. For the current stage, key technologies to implement FODSM include the algorithm of swept volume calculation and the following Boolean operation, mechanism to provide natural and intuitive feedback. This paper uses an analytical and experimental method to implement the novel design and manufacturing technology. Key issues are analyzed and tested. Experimental details are demonstrated.