Embodiments of the present invention relate to a mobile Wi-Fi access point determining method, a Wi-Fi access point-based positioning method, a Wi-Fi AP determining device, and a Wi-Fi-based positioning device. The method includes: determining a signal graph of each of a plurality of Wireless Fidelity access points Wi-Fi APs in a positioning area; estimating a Wi-Fi AP location based on the Wi-Fi AP signal graph; determining a divergence of the Wi-Fi AP signal graph based on the estimated Wi-Fi AP location; determining, based on the divergence of the Wi-Fi AP signal graph, whether the Wi-Fi AP is a mobile Wi-Fi AP; when the Wi-Fi AP is a mobile Wi-Fi AP, deleting the mobile Wi-Fi AP from a fingerprint database; and finally determining a positioning result of an apparatus whose signal strength is obtained. Positioning accuracy is improved in the embodiments of the present invention.