A thin-film transistor and a manufacturing method therefor, a display substrate, and a display device. The thin-film transistor comprises: a source electrode (1), a drain electrode (2), and an active layer (3) formed on a substrate, wherein the active layer (3) comprises a source electrode contact region in contact with the source electrode, a drain electrode contact region in contact with the drain electrode, and a channel region located between the source electrode contact region and the drain electrode contact region; and a first conductive pattern distributed in the channel region of the active layer and in contact with the channel region.