The present invention discloses a positioning tag operation method includes the steps outlined below. The positioning tag is set in an initializing state to select an available positioning time interval within each positioning periods as a selected positioning time interval and broadcast a connection request signal therein. A time synchronization signal is received from a base station of the positioning system. The time synchronization signal includes information of an assigned positioning time interval corresponding to the positioning tag within each of the positioning periods is determined by the positioning tag, so as to set the positioning tag in a positioning state accordingly and stop receiving the time synchronization signal. The positioning signal is broadcasted in the assigned positioning time interval within each of the positioning periods in the positioning state, and the positioning signal is stopped to be broadcasted in the time other than the assigned positioning time interval within each of the positioning periods.