The present invention provides an anti-lost prompting method and an anti-theft device, which can improve the accuracy of anti-lost prompting of the Bluetooth and avoid false vibration prompting in a non-lost situation. The method comprises: determining whether a step counting value in a first preset duration before an anti-theft device and a peer device are disconnected is greater than a preset value; if the step counting value is greater than the preset value, determining whether a signal quality value sequence of communication signals between the anti-theft device and the peer device is descending in the first preset duration before the disconnection; and generating an alarm if the signal quality value sequence is descending in the first preset duration before the disconnection.
