Abstract: An ultrasonic transducer array combination includes a casing and first, second, and third linear ultrasonic transducer arrays. The casing includes a first-layer housing, a second-layer housing, and a third-layer housing. The first-layer housing, the second-layer housing, and the third-layer housing are connected to each other in a stacked manner and have first, second, and third mounting surfaces in a z-shaped arrangement, respectively. The first linear ultrasonic transducer array is disposed corresponding to the first mounting surface in the first-layer housing. The second linear ultrasonic transducer array is disposed corresponding to the second mounting surface in the second-layer housing. The third linear ultrasonic transducer array is disposed corresponding to the third mounting surface in the third-layer housing, to make the first, second, and third linear ultrasonic transducer arrays spaced away from each other in the z-shaped arrangement.