The principle of the algorithm for stability near infrared (NIR) optical Tomography (CT) is introduced. The forward problem of optical CT is how to solve the Boltzmann transmitting equation based on finite rlement method (FEM). The influence of high reduced scattering coefficient and high absorption coefficient distribution of simulation background was discussed. The inverse problem is to reconstruct the map of the background tissue from the boundary data, and the image reconstruction algorithm is the key problem for optical CT. Generic algorithm (GA) and FEM simulation was used to solve the inverse problem.