Location based service brings great convenience for people's life.At present,most of the positioning services in indoor environment are based on the wireless network.However,big data makes the user's personal information no longer privacy.In particular,the service provider will obtain the user's personal location information in real timewiththe network-based positioning service.How to protect user's location information is an important issue in the big data era.This paper introduces an offline geomagnetic positioning model for indoor location data privacy protection.This model uses the accelerometer to detect pedestrian gait information and match the magnetic field information detected by the magnetometer with the fingerprint map.It can not only provideindoor location service,but also solve the problem of user's location information disclosure,thus gives an effective solution to user location privacy protection.