The present disclosure discloses an array substrate, a manufacturing method thereof, a display substrate, and a display device, belonging to the technical field of display. The array substrate includes: a flexible base, and, a TFT and a connecting line which are on a side of the flexible base. The array substrate has a display area and a lead area. The TFT is in the display area. The connecting line is in the lead area. The connecting line is used to electrically connect the TFT to a drive circuit. A manufacturing material of the connecting line includes a flexible conductive material. Since the material forming the connecting line includes a flexible conductive material, and the flexible conductive material has electrical conductivity and is not easily broken, the breaking probability of the connecting line is reduced, and the yield of the display device is effectively improved.