Abstract: Based on second-order time discretization of BDF2, this paper presents a simpler approach for designing algorithms for coupling radiation, ion and electron energies via operator splitting method. Numerical results show the error and computational cost of iterative operator splitting method is less than that of operator splitting method with the same time discretization order, and while compared with first-order backward Euler method, time steps of second-order BDF2 can be ten times lager for obtaining the same computational accuracy. This new proposed second-order time discretization iterative operator splitting method can be used for simulating ICF physical models, and promoting the computational efficiency.