The anisotropy, twophase pore and nonuniformity must be considered comprehensively in order to describe the oil and gas reservoirs accurately. Consequently a twophase anisotropic random medium model based on the twophase model and random medium theory is presented in this paper. The seismic wavefield numerical modeling was simulated by using the pseudospectral method. The results show that there exist complex wave field features such as wave scattering and traveling time disturbance and these features strongly depend on parameters of the random medium model, the nonuniformity rate mainly impacts the wave traveling time disturbance when spatial scale of nonuniformity is large and mainly impacts wave scattering when spatial scale of nonuniformity is small. The studies make it possible to retrieve the nonuniformity on statistical basis and are useful to understanding more deeply the seismic wave propagation in oil and gas reservoirs.