A system of clustering, noise reduction and visualization for Doppler ultrasound image, comprising: a capture device, being configured to obtain a plurality of Doppler ultrasound images based on a time domain, wherein each of the Doppler ultrasound image comprises a color value in each pixel; a processing device, being connected to the capture device, and comprising: a data conversion processor, being configured to arrange the color value in each pixel of the Doppler ultrasound images based on the time domain to obtain a plurality of color value sequences; a data analysis processor, being configured to calculate the color value sequences through a referencing method to obtain a reference sequence, compare the reference sequence with each of the color value sequences through a clustering method to obtain a plurality of correlation coefficient values, and classify the color value sequences into a primary pulsatile signal, a secondary pulsatile signal, and a noise signal based on the correlation coefficient values through a clustering and noise reduction method; and a data record processor, being configured to annotate the color values of the primary pulsatile signal, the secondary pulsatile signal, and the noise signal to obtain a plurality of visualized pulsatile ultrasound images; an output device, being connected to the processing device and configured to display the visualized pulsatile ultrasound images. a capture device, being configured to obtain a plurality of Doppler ultrasound images based on a time domain, wherein each of the Doppler ultrasound image comprises a color value in each pixel; a processing device, being connected to the capture device, and comprising: a data conversion processor, being configured to arrange the color value in each pixel of the Doppler ultrasound images based on the time domain to obtain a plurality of color value sequences; a data analysis processor, being configured to calculate the color value sequences through a referencing method to obtain a reference sequence, compare the reference sequence with each of the color value sequences through a clustering method to obtain a plurality of correlation coefficient values, and classify the color value sequences into a primary pulsatile signal, a secondary pulsatile signal, and a noise signal based on the correlation coefficient values through a clustering and noise reduction method; and a data record processor, being configured to annotate the color values of the primary pulsatile signal, the secondary pulsatile signal, and the noise signal to obtain a plurality of visualized pulsatile ultrasound images; an output device, being connected to the processing device and configured to display the visualized pulsatile ultrasound images. a data conversion processor, being configured to arrange the color value in each pixel of the Doppler ultrasound images based on the time domain to obtain a plurality of color value sequences; a data analysis processor, being configured to calculate the color value sequences through a referencing method to obtain a reference sequence, compare the reference sequence with each of the color value sequences through a clustering method to obtain a plurality of correlation coefficient values, and classify the color value sequences into a primary pulsatile signal, a secondary pulsatile signal, and a noise signal based on the correlation coefficient values through a clustering and noise reduction method; and a data record processor, being configured to annotate the color values of the primary pulsatile signal, the secondary pulsatile signal, and the noise signal to obtain a plurality of visualized pulsatile ultrasound images; an output device, being connected to the processing device and configured to display the visualized pulsatile ultrasound images.