A definition method for urban dynamic spatial structure circle comprising steps of: collecting the location data of mobile phone users for cleaning and handling to obtain a matched location data of mobile phone user; incorporating the matched location data of mobile phone user at various moments into a daily location data of mobile phone according to the date with a base station being the unit; locating spatially each base station with different users in a whole city through Tyson polygon processing method addressing the incorporated base station information; distributing the data of user number in each polygon into each land plot contained therein; obtaining mobile phone user distribution multi-circle numerical law on each moment and workday and finding the critical point of value, delineating the urban dynamic spatial structure circle distribution map after combining the circles in the same plot area.