An ultrasound grayscale imaging system includes a probe； a transmitting circuit which excites the probe to transmit multiple groups of non-focused ultrasound beams to a flow； a receiving circuit which receives echoes to obtain multiple groups of non-focused ultrasound echo signals； a signal processing unit which obtains flow data according to the multiple groups of non-focused ultrasound echo signals； an image processing unit which obtains B mode ultrasound image sequence according to the flow data； and a display device which displays the B mode ultrasound image sequence.
