Embodiments of the present disclosure provide a positioning system and positioning method. A reverse calibrator for respectively calibrating relative coordinates of at least three ultrasound generators; a processor for generating a carrier signal, multiplying the carrier signal with a spread spectrum pseudo random code to obtain ranging signal, controlling each ultrasound generator to emit ranging signal, and extracting acoustic characteristic parameter of the ranging signals; a device being positioned for capturing ranging signals emitted by each generator, extracting acoustic characteristic parameter of each of the captured ranging signals; determining an ultrasonic delay time of each ultrasonic ranging signal; calculating relative coordinates of the device.