In the study of visualization quantitative evaluation of cardiovascular flow, this paper presents a visualization method of cardiovascular flow velocity vector field based on color Doppler image information. The method extracts velocity component in beam direction by the Doppler image information, decompose the flow of two-dimensional observation plane into the basic flow and vortex in the light of its characteristics. Then, the velocity components of basic flow and vortex are calculated in the beam direction and the perpendicular direction to beam. Finally, the real velocity vector of each particle is obtained by synthesizing the various velocity components vector. Experiments shows that the method can effectively describe the velocity vector field of cardiovascular flow, and can provide an effective visualization basis for the evaluation of cardiac function and cardiac disease diagnose.