Transmission characteristics of optical field in 2D random medium of non-spherical particles are studied. Based on the overall scattering effect, a two-dimensional random media model of non-spherical particles as scattering particle is established. The Maxwell equations for the model are built. Using non-uniform mesh finite different time domain (FDTD) method to solve Maxwell′s equations, the transmission and spatial distribution of TM mode in the two-dimensional random medium model of non-spherical particles has been achieved. Using the data obtained from simulation, light emission spectrum in frequency domain is calculated by fast Fourier transform (FFT). Compared with previous studies, the results show that in the non-spherical particle systems, the light intensity is different from the intensity in spherical particle systems which increases with the concentration of scattering particles increasing, and it is of oscillation. The emission spectrum shows mode competitions in non-spherical particles systems are stronger than the spherical particle systems. They are easier to realize mode selection.