Abstract: A consistent linear multifrequency-grey acceleration scheme is developed to accelerate the iterative convergence speed of diamonddifferenced multigroup radiative transfer equations. A difference scheme of acceleration equation is obtained directly by applying discrete P1 approximation to differenced S_N equations. Numerical examples show that the method is effective and robust.

Key words: radiative transfer, diffusion-synthetic acceleration, diamond-differenced discrete-ordinates equations, linear multifrequeneygrey acceleration