Abstract: Based on the location fingerprint positioning method, this paper proposes an indoor positioning method based on the integration of Wi-Fi and mobile communication networks, and designs a dual-network indoor positioning system. The system stored the strength values of the Wi-Fi signal and base station signal together as the location fingerprint, used fingerprint matching algorithms such as K nearest neighbors algorithm for indoor positioning, and realized the positioning system on mobile phone. The positioning effect of the system was test through experiments, and the influence of different directions on the positioning results was explored. The results show that the positioning accuracy of the dual-network-based indoor positioning system is improved compared with single-network positioning system, and the average accuracy can reach 1.22 m under the WKNN algorithm.