Abstract: A curved handpiece for dental root canal treatment forms an overall scheme of a dental curved handpiece, which is internally conductive, surface insulated, compact in structure, small in height and size and convenient to repair. A dental root canal length measuring function can be realized accurately, safely and stably, and a stable two-in-one function of combining root canal preparation and dental root canal length measurement is further realized. The structure is compact as a whole, and a good visual field is provided. The risk of instrument separation or preparation step generation in the operation process of doctors is reduced, and the safety improvement is greatly guaranteed. According to the scheme, it is convenient to disassemble, repair and clean, the risk of cross infection is reduced, and the use safety and convenience effects of the present invention are further improved. The curved handpiece has great market benefits.