An embodiment of the invention discloses an ultrasonic ranging method and device. The ultrasonic ranging method comprises the following steps: receiving a first ultrasonic signal reflected back by an object under detection through an ultrasonic sensor array, wherein the first ultrasonic signal is the ultrasonic signal emitted by a position detection sensor and having a preset angle range; determining emission parameters of each ultrasonic sensor in the ultrasonic sensor array according to the time, when each ultrasonic sensor in the ultrasonic sensor array receives the first ultrasonic signal; and finishing range measurement of the object under detection according to the ultrasonic sensor array obtained after the emission parameters are determined. According to the technical scheme, the device and method realize range measurement of the objects, the specific positions of which are not known or which are not within the ranging angle range of the ultrasonic sensors.