The present invention relates to the field of wireless charging technology and provides a wireless charging prompt method and device, and a wireless charging system. The method includes establishing a wireless charging connection between a transmitting device and a receiving device; acquiring relative displacement information of the transmitting device and the receiving device and charging efficiency of the transmitting device charging the receiving device in real time; and generating a displacement indication according to change of the charging efficiency with the relative displacement information, where the displacement indication indicates relative movement of the receiving device and/or the transmitting device to improve the charging efficiency.