The disclosure discloses a polyacrylate dispersant, a pigment dispersion, a color photoresist, a color filter substrate and a display device. The polyacrylate dispersant of the disclosure is a polyhedral oligomeric silsesquioxane-modified polyacrylate dispersant prepared by an esterification reaction of a polyacrylate dispersant and polyhedral oligomeric silsesquioxane. Due to a steric hindrance effect of the structure of polyhedral oligomeric silsesquioxane, the polyacrylate dispersant of the disclosure may significantly improve the stability of pigment dispersion when used for dispersing pigment powder. A color photoresist prepared based on the pigment dispersion has a prominent heat resistance, an excellent resolution and a surface smoothness, as well as a low dielectric constant.