An iterative method based on the implicit TVD schemes of Harten-Yee's type is presented for the full Navier-Stokes equations with chemical source terms. Only the inviscid part of the implicit scheme is updated in every iteration, it makes the iterative algorithm convenient and economical.Numerical tests upon two-dimensional hypersonic non-equilibrium flows with five neutral air species have been taken with the present iterative algorithm. the results are compared with the conventional non-iterative ones. It is shown that the iterative algorithm accelerates the efficiency of computations. Moreover, the algorithm becomes more efficient with the increase of incoming Mach number.