The invention discloses a preordering, access and safe monitoring comprehensive management system of a parking lot, and relates to an application of internet of things built on the basis of internet, telecommunication network and positioning technology, and a comprehensive operation system mainly providing vehicle services of preordering a parking space and monitoring the parking lot and realizing effective management and service charge. Through the system disclosed by the invention, a positioning preordering mode based on a mobile terminal is established on the premise of not influencing an original service mode of the parking lot, and the safest monitoring on a vehicle is realized by a simplest manner by utilizing a three-dimensional photographic technique. Therefore, the reliability of popularization and cooperation of a project is improved. The system user does not need other hardware investment, and the system disclosed by the invention is not limited by territory and is suitable for large-area uniform popularization. The invention has the advantages of advanced technique, simpleness, practicability, stability and reliability.