An in-cell touch screen and display device, which multiplex the common electrode layer as self-capacitance electrodes using self-capacitance principle, modify the pattern of the common electrode layer to segment it into a plurality of independent self-capacitance electrodes, and add on the array substrate touch control data lines that connect the respective self-capacitance electrodes to the touch control detection chip. Orthographic projections of the respective touch control data lines on the array substrate are all within areas where gaps between the pixel areas reside, so as to not affect the aperture ratio of pixel. Embodiments of the present invention modify the structure of the common electrode layer to segment it into self-capacitance electrodes, thus avoiding additional processes of manufacturing an array substrate, saving the production cost, and improving the production efficiency.