The invention provides a demographic deduplication method, which comprises the following steps of a, taking a crowd trajectory record, and recording the crowd trajectory record as [(mobile, lng, lat,timestamp), (mobile, lng, lat, timestamp)...],b, aggregating the records in the step a by taking the mobile as an element, sorting according to the time sequence of timestamps, and recording an aggregation result as (mobile, List(lat, lng)),c, sequentially calculating the distance between trajectories of the trajectory data in the step b by using a dynamic time warping algorithm,and d, comparing the distance in the step c with a reference value to judge whether the calculated mobile phone number is the same person. Visibly, signaling data is generated through the mobile terminal and the base station, possible repeated crowds are counted and analyzed, the population quantity of a certain region can be calculated more efficiently, timely and accurately in a simple manner, and the method hasextremely important social significance.