An ultrasonic imaging device includes an ultrasonic generating unit and an ultrasonic imaging processing unit. The ultrasonic generating unit repeatedly turns on N of M ultrasonic array elements of the ultrasonic probe multiple times as a group of array elements for linear scanning, and each scan is to emit an ultrasonic signal by each group of array elements and receive an echo signal of the ultrasonic signal. The ultrasonic imaging processing unit extracts a central echo signal from the echo signal in each scan to form a channel signal, and according to the arrival time of the echo signals, each central echo signal in the channel signal is delayed and summed to generate a modified channel signal. The modified channel signal is subjected to image synthesis process to obtain an ultrasonic image.
