The invention discloses a device for field construction and fast positioning of electric power tower. The device includes a small round chassis, a large round chassis, an operation device, a central light set and an auxiliary positioning device, wherein the central light set is installed on the small round chassis, and the auxiliary positioning device is installed on the operation device. Quick assembly, quick orientation, rapid calibration and rapid positioning at a construction site can be achieved, the optical positioning accuracy is high, errors are small, the device is not affected by wind, rain and dust in the wild, the device is convenient to adjust, disassembly is simple, the occupation space is small after disassembly, the device is convenient to handle, labor and time are saved,and the whole positioning operation can be completed by only one person.