According to the theory of first-order Born approximation,a Fourier Domain Optical Coherence Tomography(FDOCT) model of single scattering infinite narrow beam is established,and the reason why it is hard to obtain the exact solution of integrated scattering equation is analyzed.The Monte Carlo simulation results indicate that two kinds of photon are different in spatial distributions.The multiple backscattering photons can be rejected and more single backscattering photons can be received by adjusting the detection area.Then,the advantage of FDOCT is confirmed by analyzing the differences between Time Domain OCT(TDOCT) and FDOCT.The simulation results provide an important reference for experiments.The gray level distortion of complex bio-tissue image resulting from energy attenuation can be approximately compensated by changing the model's structure.