Over the last few decades, the application of conventional piles as a method of mitigating landslides or preventing instability on stable slopes has become an effective technique for reinforcing slopes. In recent decades, stabilizing the slopes using micropiles has become an alternative to conventional piles for reinforcing a diverse range of slopes because of their effective performance and faster construction techniques. This study employed PLAXIS 2D to conduct numerical modelling, aiming to examine the implications of various parameters affecting the stability evaluation of slopes that have been reinforced with micropiles. Additionally, the study aimed to optimize a series of micropiles in cohesive-frictional soil slopes. This method uses the shear strength reducing technique, that describes the soil behavior based on the Mohr-Coulomb criteria. The model represents the micropiles as 2D embedded beams. A series of stability of slope analyses are conducted for predicting the most optimal location and length of the micropiles. The dominating coupled effect between micropiles, and slope has been observed, and the location of the micropile system has a significant effect not only on the calculation of the safety factor but also on the determination of the failure surface.