A kind of object for improving the blood in the blood vessel for measuring flow velocity is provided, this method includes to emit supersonic beam using ultrasonic transducer to measure the theme in a part of ontology of flow velocity A part of ontology of a space moment VELOCITY DISTRIBUTION is formed from actual measurement flow velocity The angle to determine the correction ultrasonic beam of space time VELOCITY DISTRIBUTION is analyzed relative to the theme, which is based on the position of different peak values, in the space time VELOCITY DISTRIBUTION, the time rate curve at center and space.
