Ultrasonic positioning method, device and system

An embodiment of the invention provides an ultrasonic positioning method, device and system. The ultrasonic positioning method comprises sending a first ultrasonic signal from a reference point to a point to be measured, and recording signal sending time; receiving a second ultrasonic signal at the reference point, recording signal receiving time, enabling the second ultrasonic signal to be a responding signal after the first ultrasonic signal is received at the point to be measured, and enabling the frequency of the first ultrasonic signal and the frequency of the second ultrasonic signal to be different; and positioning the point to be measured according to the signal sending time, the signal receiving time and the position of the reference point. By enabling the frequency of the ultrasonic signal sent at the reference point to be different from the frequency of the frequency fed back by the point to be measured, the multipath effect in the ultrasonic propagation process and positioning disturbance caused by the ultrasonic wave reflected by other subjects are avoided, and the accuracy of ultrasonic positioning is improved.