The invention discloses an indoor positioning method for a mobile terminal, which belongs to the field of mobile communication. The method includes the following steps: 1, modifying a fingerprint format of a Wi-Fi positioning reference area in a server; 2, enabling a client to enter the positioning reference area, enabling an inertial navigation module program to read user step and direction information detected by a sensor, tracking a walking trajectory of a user by using a particle filtering mode, and calling a Wi-Fi positioning module based on an RSS fingerprint to implement positioning; 3,enabling a particle filtering module program of the client to globally search for a position P1 with the highest density; 4, if the density of P1 is less than a threshold, enabling the particle filtering module program of the client to perform positioning; and 5, if the density of P1 is greater than the threshold, enabling an evaluation calibration module program of the client to perform correction. According to the scheme of the invention, the positioning accuracy can be improved, and the calculation amount of repeated data acquisition for updating a Wi-Fi offline fingerprint database can also be avoided.