Micro/nano manipulation technologies have shown enormous potential in the field of accurate surgery, which is expected to promote the development of precision medicine. Therefore, scientists have been devoted to designing and manipulating nanoscale devices and tools which can conduct surgical functions, such as penetration, drilling and cleaving targeting either single cells or biological tissues. To enrich the functionality of the family of nanomachines, a theoretical nanoscale telescopic arm manipulated by charge-tunable multi-walled carbon nanotubes is designed in this work. By using predesigned encoding strategies that could periodically alternate the external electric fields and surface charge densities of the nanorings embedded in the carbon nanotubes, well controlled manipulations of the telescopic arm are realized in MD simulations to mimic nanoscale surgeries. The telescopic arm can stretch out by the external electric force and draw back by vdW attraction between the nested nanotubes. Meanwhile, the electric double layer formed around the nanoring area in the nanotube is used as a brake during the retraction process to make the nanotube halt stably at the target position. The working distance could also be tuned by changing the number of the nested nanotubes, which presents a promising avenue for varieties of biomedical applications.