Foucault is a highly challenging, rebellious, creative, and disruptive thinker who has a close relationship with Marxism. Foucault's academic activities have raised three major issues, namely the question of truth, power and personal behavior. The issue of power is the core of Foucault's thoughts and is the 'eye' of modernity. Foucault's unique micro-perspective to uncover the veil of power and criticize modern society is fundamentally different from Marx's examination of modernity from the perspective of totality. This article compares Marx's and Foucault's power ideology to further understand the connotation of the two power ideas and enhance the understanding of modernity.