The most essential difference between color ultrasound and B-ultrasound is that B-ultrasound is the basis of color ultrasound, and color ultrasound is developed on the basis of B-ultrasound and can be seen as an upgraded version of B-ultrasound. The imaging method of B-ultrasound is mainly in grayscale, which is what we call brightness, and the imaging method of color ultrasound is in grayscale plus ultrasound Doppler together. What they have in common is that they can both see the shape and size of tissues and organs and the presence or absence of occupying lesions. The biggest difference is that color ultrasound can show the blood flow within tissues and organs and abnormal occupying sites, which is more instructive for the diagnosis of some diseases. Therefore, color ultrasound can simply be seen as an advanced version of B-ultrasound, but the essence is the same as B-ultrasound. Each ultrasound instrument contains five types of ultrasound diagnostic methods: B-mode, M-mode, PW, CW and CDFI. The addition of color Doppler and spectral Doppler images to the ultrasound images can provide an understanding of the distribution of blood flow and the flow rate. Both ultrasound and color ultrasound have imaging limitations and distortion artifacts.