This paper focuses on the problem of data representation and explanation of three-dimensional volume data field based on the physics model of the data．First the data model is set up by three-dimensional geometry model．Then the surfaces are extracted from the data field and match with the model to reconstructure the data field based on the Dhysics model．This paper also presents a subdivision algorithm to fast trace B-spline curve and the anti-approach iS adopted to evaluate the control polygon ot the curve in order to extract the geometry feature．