Because the number of tetrahedral elements in three dimensional field division is too great and will need too much computer memory and run time,the control volume finite element method based on parallelepiped elements is presented. In this method,the number of elements is much smaller and the number of points is egual to that in using tetrahedral elements. The divergence theorem can be used to translate the volume integral into the surface integral corresponding to the same control volume of grid points so that the upwind interpolated scheme for convection variables can be used. Through three test problems,it is proved that this method is valid for numerical simulation of three dimensional fluid flow and heat transfer under the limit of computer memory and run speed.