A three-dimensional imaging ultrasonic scanning method applicable to ultrasonic diagnostic instruments, including following steps: generating a high-frequency voltage pulse for driving a plurality of ultrasonic arrays and powering a spatial locator to operate; acquiring different ultrasonic image information of a tested object by the plurality of ultrasonic arrays, wherein the plurality of ultrasonic arrays respectively send ultrasonic waves to the tested object, receive ultrasonic echo from the tested object and output corresponding electrical signals according to the ultrasonic echo and further wherein the plurality of ultrasonic arrays have different size, focus modes, shapes and the combinations thereof; further wherein the mounting orientations of the plurality of ultrasonic arrays are different and images of multiple desired scanning areas or images of the same scanning area in different directions are obtained by one time of scanning; acquiring positional information of the plurality of ultrasonic arrays by the spatial locator; the spatial locator is a motor driving device with a positioning function, the motor driving device with the positioning function is a circular scanning device; the circular scanning device includes a motor driver and a supporting body driven by the motor driver to rotate; the supporting body has a circular shape; the tested object is placed at the center of the supporting body; the plurality of ultrasonic arrays are mounted on the supporting body and equally spaced along the circumference of the supporting body; and the three-dimensional imaging ultrasonic scanning method further comprises: reconstructing a three-dimensional image of the tested object based on the different ultrasonic image information of the tested object and the positional information of the plurality of ultrasonic arrays; wherein said positional information is acquired by the spatial locator and said ultrasonic image information is acquired from the electric signals outputted by the plurality of ultrasonic arrays after image processing. generating a high-frequency voltage pulse for driving a plurality of ultrasonic arrays and powering a spatial locator to operate; acquiring different ultrasonic image information of a tested object by the plurality of ultrasonic arrays, wherein the plurality of ultrasonic arrays respectively send ultrasonic waves to the tested object, receive ultrasonic echo from the tested object and output corresponding electrical signals according to the ultrasonic echo and further wherein the plurality of ultrasonic arrays have different size, focus modes, shapes and the combinations thereof; further wherein the mounting orientations of the plurality of ultrasonic arrays are different and images of multiple desired scanning areas or images of the same scanning area in different directions are obtained by one time of scanning; acquiring positional information of the plurality of ultrasonic arrays by the spatial locator; the spatial locator is a motor driving device with a positioning function, the motor driving device with the positioning function is a circular scanning device; the circular scanning device includes a motor driver and a supporting body driven by the motor driver to rotate; the supporting body has a circular shape; the tested object is placed at the center of the supporting body; the plurality of ultrasonic arrays are mounted on the supporting body and equally spaced along the circumference of the supporting body; and the three-dimensional imaging ultrasonic scanning method further comprises: reconstructing a three-dimensional image of the tested object based on the different ultrasonic image information of the tested object and the positional information of the plurality of ultrasonic arrays; wherein said positional information is acquired by the spatial locator and said ultrasonic image information is acquired from the electric signals outputted by the plurality of ultrasonic arrays after image processing.