Molybdenum disulfide (MoS2 ) is the best example of two-dimensional (2D) materials with intrinsic atomic-level thicknesses which are strong candidates for the development of deeply scaled field-effect transistors (FETs). Focusing on this material because of their non-zero band gap, mechanical flexibility, and optical transparency. In this research, an efficient model of MoS2-FETs that is based on simulating the 3D geometry by using the COMSOL Multiphysics software have been presented. We study different models of FETs simulations: (1) Mono-layer of MoS2 (2) Four-layers of MoS2 (3) MoS2 Transistor with HfO2 (4) MoS2 Transistor with Hf0.3Zr0.7O2 and compare between them. The best result has been obtained when using MoS2 Transistor with Hf0.3Zr0.7O2 which obtained the largest drain current comparing with other issues. From overall evaluation, we can state that our model provided good results also for this different kind structure when change of the thickness of MoS2 . This indicates that the change of thickness greatly affected on the efficiency of FET transistor.