An OLED array substrate and a manufacturing method thereof, and a display device provided with the OLED array substrate are disclosed. The OLED array substrate includes a plurality of thin film transistors (2) disposed on a base substrate (1), each thin film transistor (2) being provided with a black matrix (6) thereon, and the black matrix (6) being provided with a via (60); over the black matrix (6) being disposed from bottom to top a first electrode (41), a luminescent layer (43) and a second electrode (42). The first electrode (41) is connected with the thin film transistor (2) through the via (60), and the first electrode (41) disposed over adjacent thin film transistors (2) are separated from each other by a barrier (44). The black matrix can block light emitted by the OLED to prevent TFTs from being illuminated, thereby ensuring the display effect of an active matrix type OLED display device.