A wearing prompt method for a wearable device and an apparatus, and related to the field of communications technologies, to reduce a probability that the wearable device cannot accurately measure physiological parameters of a user, thereby improving accuracy of measuring the physiological parameters of the user. The method includes: obtaining, by the wearable device, a target PPG (photo plethysmo graph) signal; and prompting, by the wearable device when the target PPG signal is inconsistent with a stored reference wearing parameter, a user to adjust a wearing position of the wearable device and to adjust tightness of wearing the wearable device.