Provided are a low-power ultrasound sensor that detects whether an object exists at a high speed, an object detecting method of the ultrasound sensor, and a computer-readable storage medium. The ultrasound sensor may include: a transmitter that outputs a plurality of first ultrasound beams having different frequencies; a receiver that receives a first reflection signal that is output when the output plurality of first ultrasound beams are reflected from an object; and a controller that determines a first area in a space, controls the transmitter to respectively output the plurality of first ultrasound beams to a plurality of first sub-areas that are included in the first area, and determines whether the object is included in each of the plurality of first sub-areas, based on the first reflection signal.