This paper presents the study on the formation of surface layer in A359/20SiCP metal matrix composite (MMC) during laser assisted turning, with the consideration of SiC particles’ sedimentation in a liquid matrix. The developed model includes the effect of gravity, buoyancy, resistive force of liquid matrix and centrifugal force of the rotating work material. On the basis of the proposed approach the instantaneous sedimentation speed, as well as the depth of sedimented SiC particles are calculated. Consequently, the applied model enables the selection of the effective depth of cut and tool’s angular distance from the laser beam, which can improve the machined surface quality and composite’s exploitation properties. The experiments confirm that sedimentation phenomenon plays an important role during the surface layer formation in laser heating conditions. Furthermore, the laser assisted turning with the selection of the recommended cutting conditions affects the improvement of surface quality, and composite’s wear resistance.