The production mechanism of heavy neutronrich nuclei is investigated by using the multinucleon transfer reactions of ~(136;148)Xe+~(208)Pb and ~(238)U+~(208)Pb in the framework of a dinuclear system model. The evaporation residual cross sections of target-like fragments are studied with the reaction system ~(148)Xe+~(208)Pb at near barrier energies. The results show that the final isotopic production cross sections in the neutron-deficient side are very sensitive to incident energy while it is not sensitive in the neutron-rich side. Comparing the isotopic production cross sections for the reactions of ~(208)Pb bombarded with stable and radioactive projectiles, we find that neutron-rich radioactive beams can significantly increase the production cross sections of heavy neutron-rich nuclei. The production mechanism of heavy neutron nuclei is investigated by using the multinuclear transfer reactions of ~ (136; 148) Xe + ~ (208) Pb and ~ (238) U + ~ (208) Pb in the framework of a dinuclear system model. residual cross sections of target-like fragments are studied with the reaction system ~ (148) Xe + ~ (208) Pb at near barrier energies. The results show that the final isotopic production cross sections in the neutron-deficient side are very sensitive to incident energy while it is not sensitive in the neutron-rich side. Comparing the isotopic production cross sections for the reactions of ~ (208) Pb bombarded with stable and radioactive projectiles, we find that neutron-rich radioactive beams can significantly increase the production cross sections of heavy neutron-rich nuclei.