In the power Internet of Things (IoT), non-line-of-sight (NLOS) error is an important factor affecting the stability and accuracy of position estimation. At present, there are many technologies to eliminate NLOS errors, with the prior information about the NLOS channel. This paper proposed an improved residual weighted location estimation algorithm in NLOS environment. Based on the principle of minimum residual error, the novel method continuously removes the base station with the largest NLOS error through calculation, and uses the residual value to weight the different base station combination results. The weighted result is the final positioning result. The experimental results show that the proposed algorithm has good positioning accuracy in the NLOS environment of power IoT without prior information about the NLOS channel.