Wall boundary conditions for the macroscopic equations, i.e. the NSF(Navier-Stokes-Fourier) equations, R13/R26 moment equations, lose their accuracy dramatically and are easy to diverge, especially in the middle and high Knudsen number regimes.To overcome these difficulties, a wall boundary condition for the R13/R26 moment method was proposed at the mesoscopic level. The velocity distribution function was reconstructed and feedback into the Boltzmann model equation in the near-wall region, and the wall boundary condition for the R13/R26 moment method was calculated on the basis of solving the Boltzmann equation with the discrete velocity method. Results indicate that:the proposed wall boundary condition is able to increase the computational accuracy up to 59.84% compared with the classical approach. Meanwhile, it is able to get the steady-state solution for the Knudsen number up to 1.0.