Aiming at problem of low positioning precision and blind zone of localization of BeiDou（ BD） and WiFi single system

an indoor and outdoor fusion localization method based on BD difference and WiFi is proposed.According to heterogeneous network of BD and WiFi

multi-attribute cost function is established to choose optimum positioning constellation and beacon group. The pseudo-range difference method of multi datum stations based on inverse distance weighted interpolation is adopted to modify the BD pseudo-range equation and reduce space pseudo-range error. Constructed the WiFi ranging equation based on the received signal strength indication（ RSSI）propagation model and fused the BD differential pseudo range equation. The Taylor iterative algorithm is adopted to positioning. Simulation results show that the fusion positioning accuracy can reach 2. 6 m in 95 % probability

and the location performance is better than BD and WiFi alone. This method can solve the problem of low positioning accuracy and blind zone of a single system effectively

which achieves the indoor and outdoor seamless fusion precise positioning and improves the positioning accuracy and reliability.