The invention discloses an access control system of a parking lot. The access control system is high in intelligent degree, low in cost and capable of achieving rapid detection, interaction and authentication. The access control system comprises a road gate located at the entrance of the parking lot, and a controller used for controlling the gate way. The access control system further comprises a server, a drive test unit and a mobile phone client side. The drive test unit comprises a WiFi communication module and an iBeacon receiving module. The mobile phone client side comprises an iBeacon transmitting module. The access control system is high in intelligent degree. Meanwhile, users doe not need to add any accessory hardware, and the use cost is reduced to the users; furthermore, the system can achieve rapid detection, interaction and authentication and is high in positioning accuracy and authentication passing rate and low in false detection probability; in addition, the system has high safety and can ensure safety detection, and only authenticated vehicles can pass. The access control system is suitable for being applied and popularized in the field of access control systems.