The porosity of gas coal samples was tested. On such a basis, this paper deals with the relationship between the elastic anisotropic coefficients and the porosity of the gas coal samples, and the result shows that the value of anisotropic coefficient is to a certain extent related to porosity. This paper simulates the one-order stress-velocity equation with the staggered grid high-order difference method, and analyses the stability and boundary conditions. The simulations of Thomsen show that, in the wave simulation with the staggered-grid high-order difference method,ε denotes the anisotropic degree of of P-wave,and δ is the changing degree of transverse and vertical anisotropy of P-wave. The result is of important significance for studying the anisotropy of a coal field.