Among the various additive manufacturing processes, there is selective laser sintering, with the use of a high-power laser that sinters the small particles of polymer powder and turn them into a solid structure, from a 3D model, nowadays SLS additive manufacturing has become the best choice for the industry, especially for polymer materials, SLS ensures high productivity and well-honed materials at low cost. Recent Advances in Fitting, the materials and software have made SLS printing accessible to a wider range of activities. Our study is to show the mechanism of polymer particle suspension during the three stages of SLS printing, we start with printing first, the polymer powder in a thin layer applied on a flat shape inside the build chamber and the printer will heat the powder until the polymer melts, Allowing the laser to easily increase the temperature in specific areas in the powder bed to trace the morphology of the solidified part. Secondly, cooling and finally post-processing to extract the finished parts from the build chamber. In our study, we will analyze the suspension of small polymer powder particles in the SLS printing process. We will start with the mathematical formulation of the problem with an experimental study of the polymer sample studied. Next, we will set up the chosen solution method and finally the modeling of the results obtained on the FORTRAN language.