GPS is difficult to solve the problem of positioning in large indoor places such as stores and warehouses, so using WiFi for positioning has become the mainstream indoor positioning method. However, most of the location fingerprint methods used in WIFI positioning have some shortcomings, such as low fault tolerance and weak anti-noise ability. To solve these problems, a WIFI indoor positioning method based on Kalman filter is proposed. After obtaining RSSI values, the optimal distance is estimated by Kalman filter, and then the optimal position is calculated by triangular centroid method, Kalman filter is adopted to calculate the optimal value finally.