A wearing prompt method for a wearable device, comprising: obtaining, by the wearable device, a target photoelectric plethysmography PPG 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, to adjust tightness of wearing the wearable device; wherein the reference wearing parameter is a PPG reference signal formed when the user wears the wearable device in a reference wearing position; and the 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 comprises: prompting, by the wearable device when the target PPG signal is inconsistent with the PPG reference signal, the user to adjust the wearing position of the wearable device wherein the prompting, by the wearable device, the user to adjust the wearing position of the wearable device comprises: prompting, by the wearable device, the user to adjust a current wearing position on a wristband of the wearable device to the reference wearing position; wherein the wearable device stores a correspondence between N wearing positions on a wristband and N PPG signals, the N wearing positions comprise the reference wearing position, the N PPG signals comprise the PPG reference signal, and N>1; and after the obtaining, by the wearable device, a target PPG signal, the method further comprises: determining, by the wearable device based on the correspondence, a target wearing position corresponding to the target PPG signal; and determining, by the wearable device by comparing the target wearing position with the reference wearing position, to loosen or tighten the wristband. obtaining, by the wearable device, a target photoelectric plethysmography PPG 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, to adjust tightness of wearing the wearable device; wherein the reference wearing parameter is a PPG reference signal formed when the user wears the wearable device in a reference wearing position; and the 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 comprises: prompting, by the wearable device when the target PPG signal is inconsistent with the PPG reference signal, the user to adjust the wearing position of the wearable device wherein the prompting, by the wearable device, the user to adjust the wearing position of the wearable device comprises: prompting, by the wearable device, the user to adjust a current wearing position on a wristband of the wearable device to the reference wearing position; wherein the wearable device stores a correspondence between N wearing positions on a wristband and N PPG signals, the N wearing positions comprise the reference wearing position, the N PPG signals comprise the PPG reference signal, and N>1; and after the obtaining, by the wearable device, a target PPG signal, the method further comprises: determining, by the wearable device based on the correspondence, a target wearing position corresponding to the target PPG signal; and determining, by the wearable device by comparing the target wearing position with the reference wearing position, to loosen or tighten the wristband. prompting, by the wearable device when the target PPG signal is inconsistent with the PPG reference signal, the user to adjust the wearing position of the wearable device wherein the prompting, by the wearable device, the user to adjust the wearing position of the wearable device comprises: prompting, by the wearable device, the user to adjust a current wearing position on a wristband of the wearable device to the reference wearing position; wherein the wearable device stores a correspondence between N wearing positions on a wristband and N PPG signals, the N wearing positions comprise the reference wearing position, the N PPG signals comprise the PPG reference signal, and N>1; and after the obtaining, by the wearable device, a target PPG signal, the method further comprises: determining, by the wearable device based on the correspondence, a target wearing position corresponding to the target PPG signal; and determining, by the wearable device by comparing the target wearing position with the reference wearing position, to loosen or tighten the wristband. prompting, by the wearable device, the user to adjust a current wearing position on a wristband of the wearable device to the reference wearing position; wherein the wearable device stores a correspondence between N wearing positions on a wristband and N PPG signals, the N wearing positions comprise the reference wearing position, the N PPG signals comprise the PPG reference signal, and N>1; and after the obtaining, by the wearable device, a target PPG signal, the method further comprises: determining, by the wearable device based on the correspondence, a target wearing position corresponding to the target PPG signal; and determining, by the wearable device by comparing the target wearing position with the reference wearing position, to loosen or tighten the wristband. determining, by the wearable device based on the correspondence, a target wearing position corresponding to the target PPG signal; and determining, by the wearable device by comparing the target wearing position with the reference wearing position, to loosen or tighten the wristband.