The invention provides a navigation method and a system, a map data management cloud end and a data updating method thereof. According to the navigation method, the map data management cloud end carries out calculation according to a navigation request of a user and the collected real time road condition information to obtain an optimal path, and the optimal path is continually updated in a navigation process. A mobile terminal of the user can obtain an optimal navigation path under the real time road condition, the navigation practicability is improved, and the experience of the user is further improved; meanwhile, the system can collect the real time road condition information in the navigation process so as to send a data storage operation node, and the data storage operation node timely calibrates and updates the stored map data; and all the practicable road condition information downloaded by a path plan operation node is more overall, and the real time property and the integrality of an off-line map downloaded by a mobile terminal are improved.