A detection substrate and a display device are disclosed. The detection substrate includes an outer detection electrode and an inner detection electrode on a base substrate and insulated from each other. The outer detection electrode has a hollowed portion, and the hollowed portion corresponds to the inner detection electrode. The inner detection electrode includes a body portion and a plurality of protrusion portions protruding from the body portion and extending in directions away from the body portion. The edge of the hollowed portion includes a curved portion, an orthographic projection of the curved portion on the base substrate protrudes into a region between orthographic projections of at least two adjacent protrusion portions of the plurality of protrusion portions on the base substrate, a portion of the orthographic projection of the curved portion is closer to an orthographic projection of the body portion on the base substrate.