Abstract: High definition map not only supports the accurate positioning and fine path planning of autonomous vehicles, assists in improving the perception capability of the vehicle end, but also effectively makes up the performance boundary of sensors to deal with a variety of long-tail scenarios. Therefore, high definition map has become essential for achieving L4/L5 unmanned driving at this stage. However, high definition map belongs to the basic strategic information resources of the country, involving military and national defense security. Therefore, in terms of policy, China requires high definition map to undergo geographic information confidentiality processing before public application and to comply with map review procedures. This leads to many limitations in the expression of elements and attributes in high definition map, as well as a lack of dynamic updating ability, making it difficult to accurately reflect the driving environment information of vehicles, seriously affecting the safety and stability of autonomous driving, and making it difficult to break through the “last mile” of unmanned driving. We focus on the issues of geographic information security and timeliness in applying high definition maps for L4/L5 unmanned driving. We comprehensively discuss the current situation, practical needs, and challenges of high definition maps application. Based on this, from policy, technology, standards, pilot exploration, and other aspects, we study and analyze the safety and compliance application trend of high definition maps in the commercialization of unmanned driving in China, and provide prospects for map management innovation, large-scale implementation of crowdsource update models, multi-dimensional collaboration, and cross-departmental, interdisciplinary, and cross-industry cooperation that are urgently needed in the process of high definition maps promoting unmanned driving landing in China.