The invention discloses a positioning and navigation device for a power grid inspection and overhaul site. The positioning and navigation device comprises a data receiving terminal, a data sending terminal and a safety isolation device, wherein the data receiving terminal is connected with the data sending terminal in a wireless manner; the data sending terminal is connected with a GIS system of a power grid through the safety isolation device. The positioning and navigation device has the effects that the working efficiency is greatly improved; previously, when an inspector works, the time is wasted because the inspector is unfamiliar with the geographic position, and the working efficiency is affected. The use of mobile phone navigation software can replace the conventional method, the working time is saved, and the working efficiency is improved; the information safety of the geographic position is effectively guaranteed; in running of the whole task flow, data information cam be encrypted, and the safety of the geographic information is effectively guaranteed; the operation and maintenance cost is lowered; the inspector can quickly and effectively position an inspection position and acquire relevant information through the positioning and navigation device, and the operation and maintenance cost is greatly lowered.