The disclosure provides a display substrate, a fabrication method thereof and a display device. The display substrate includes a base, and has a display area and a frame area. The method includes: forming an active region of a thin film transistor in the display area; forming a first lead in the frame area; forming a buffer layer directly covering the first lead; forming a connection via hole communicating with the active region; forming a protective layer directly covering the buffer layer in the frame area; cleaning the active region exposed by the connection via hole after forming the protective layer; removing the protective layer in the frame area after cleaning; and forming a second lead in the frame area after removing the protective layer, an orthographic projection of the second lead on the base and an orthographic projection of the first lead on the base at least partially overlap.