Flow around a square cylinder with porous media is numerically simulated by means of the lattice Boltzmann equation in Darcy-Brinkman-Forchheimer force model, and influence of porous media on flow field characteristics of bluff body is studied. It shows that: Compared with a impermeable cylinder, the flow structure is modulated by the porous media layer under certain parameters. Evolution of the shear layer tends to be more symmetrical and stable, which reduces the interaction of vortex motions in the wake region and makes the vortex shedding more periodic, thus reducing effectively the amplitude of lift fluctuation, but increasing the drag in some extent. At the same time, we study surface porous media effect on square column under high Reynolds number. It shows that the porous medium wall makes wake region of the shear layer farther apart, reduces the wake turbulence kinetic energy, and moves the Reynolds stress peak of the mobile to wake region, suppresses the momentum exchange on either side of the square column, makes the momentum exchange occurred in wake region and the vortex street of the wake more regular.