The invention relates to an active radio frequency identification (RFID) electronic tag and an internet of things system and an internet of things method for managing parking places. In the electronic tag, a power supply unit, an infrared emission unit, an infrared sensing unit, a control unit, a tag storage area and a radio frequency unit are arranged in an external package; in the system and the method, the occupation states of the parking places are sensed in real time by installing the novel active RFID electronic tag in which the infrared sensing unit is embedded at each parking place; the parking place states stored in the tag are acquired to a parking place management system in real time through an RFID reader-writer; and the idle states or the occupation states of the parking places are graphically displayed in a guide indicator. In an inside/outside parking lot, the usage conditions of all the parking places can be accurately mastered by using the system, large-size wired or wireless network deployment is not needed in the parking lot, the information acquisition and the transmission of all parking places can be realized only by arranging a small quantity of RFID readers-writers, so that the engineering quantity and the cost of system implementation are reduced, and convenient, fast and high-quality parking guide service is provided for clients.