Abstract: Numerical simulation for three-dimensional diffusion equation is studied. Using integral interpolation method, the difference scheme on the irregular hexahedral grid is constructed which consists of 27 neighboring grids and is available for solving quasi-linear diffusion equation with discontinuous coefficients on distortion mesh. Flow flux through interfaces and temperature on the nodes are deduced and numerical test is given.

Key words: integml interpolation method, irregular hexahedml grid, three-dimensional diffusion equation, difrerence scheme