A pixel circuit and a driving method therefor, an array substrate and a display device are provided. The pixel circuit includes a driving circuit, a data writing circuit, a first initialization circuit. The driving circuit is configured to control a driving current; the data writing circuit is configured to write a data signal into the control terminal of the driving circuit; the first initialization circuit is configured to apply a first initialization voltage to the control terminal of the driving circuit, and includes a first transistor; the data writing circuit includes a second transistor and the driving circuit includes a third transistor; semiconductor materials of active layers of both the first transistor and the second transistor have a smaller leakage current characteristic than a semiconductor material of a third active layer of the third transistor.