The embodiment of the invention provides a shift register unit, a shift register circuit, an array substrate and a display device, relating to the field of display device manufacturing. An OLED (Organic Light-Emitting Diode) display device can be avoided from flashing when display data is written in. The shift register comprises a first pull-up unit, a first pull-down unit, a pull-down switch unit, a second pull-down unit and a second pull-up unit. The embodiment of the invention is applied to the manufacturing of display devices.