Aiming at the problem of the lack of effective traffic guidance and navigation in the complex underground road environment, the shortcomings of the existing indoor positioning technologies were analyzed and discussed. The underground vehicle positioning and navigation system suitable for ordinary mobile phone was studied. Through the study of radio frequency matrix base stations, positioning and navigation engines suitable for complex underground environments, combined with ordinary smart phone, an underground vehicle navigation solution with low latency, high accuracy and high reliability has been realized. At the same time, a demonstration application of underground positioning and navigation was carried out at the Suzhou center. The results showed that the system can meet the positioning and navigation needs of vehicles in the underground environment, with common mobile navigation apps, and provide drivers with a seamless, stable and efficient connection between the ground and the underground.