The scalpel is the most practical tool for surgeons. The traditional scalpel is a blade with a split handle, but the length of the blade cannot be adjusted, and it is easy to scratch medical staff. In order to solve the above problems, a retractable scalpel handle was designed by the medical staffs of department of general surgery, Affiliated Hospital of Yangzhou University (Clinical Teaching Hospital of Dalian Medical University), and obtained the National Utility Model Patent of China (ZL 2019 2 0203154.9). The telescopic scalpel adopted the design of rotary telescopic sleeve and threaded column handle to achieve the purpose of built-in blade. By rotating the handle at one end of the handle, the length of the surgical blade extending out of the sleeve could be adjusted according to the actual needs. The structure of the device is simple and easy to operate. The adjustable blade length could also achieve the purpose of accurate operation while effectively avoiding the injury of medical personnel during the operation.