The multipath propagation of WiFi signals is strongly restricted by the indoor environment.The screening and blocking of obstacles cause the signal transmission of some accept points（ AP） to be refracted and diffracted

which weakens the signal strength.Therefore

the results based on received signal strength indication（ RSSI） ranging is likely to produce a large measurement error comparing with real distance.Compared with other indoor positioning technologies

WiFi indoor positioning technology based on RSSI ranging has great advantages in positioning precision

power consumption and cost.A new localization algorithm which combines the method of multi-directional grouping RSSI ranging with the weighted centroid algorithm is proposed.This algorithm uses multi-directional ranging to reduce the measurement error caused by the screening and blocking of obstacles in RSSI.Thus

indoor positioning precision is increased by nearly 40%.