Privacy protection method for mobile terminal during running position-based service

The invention discloses a privacy protection method for a mobile terminal during running position-based service. The privacy protection method makes an attacker cannot distinguish the position of a user through a k-anonymity principle so as to protect the position privacy. An anonymous server constructs a quad-tree data structure, a plane space is recursively divided into four square zones with the same area, each user in each square zone sends a position privacy requirement Q {Pos (x, y), k, dist} to the anonymous server, the anonymous server constructs a data structure for each leaf node of the quad-tree according to the anonymous privacy requirements of the users, wherein the position privacy requirements of all the users in each square zone are stored in the anonymous server, and the anonymous server can quickly query the users who meet the anonymity degree k and space tolerance dist in the zone with the user according to the data structure maintained by the leaf node of the user and form an anonymous zone.