Real-time force and visual information during MWCNT manipulation is required for online controlling MWCNT assembly based on atomic force microscope (AFM). Here real-time three-dimensional (3D) interactive forces between probe and sample are obtained according to PSD signals based on the proposed force model, and MWCNT manipulation process can be online displayed on the visual interface according to probe's position and applied force based on the proposed MWCNT motion model. With real-time force and visual information acquisition and feedback, the operator can control online MWCNT's manipulation process by adjusting the probe's 3D motion and applied forces. MWCNT push and assembly experiments verify the effectiveness of the method, which will be used in assembling MWCNT based nano device.