The present disclosure provides a pixel circuit, its driving method, an array substrate and a display device. The pixel circuit includes a plurality of pixels, each of which includes a blue sub-pixel and a driving module for driving the blue sub-pixel. The blue sub-pixel includes N blue OLEDs, and N is a positive integer greater than 1. The driving module is configured to drive the N blue OLEDs in a time division manner. According to the present disclosure, the blue sub-pixel is segmented into several portions, and merely a portion of the blue sub-pixel is displayed each time. As a result, it is able to prolong the service time of the blue sub-pixel, thereby to increase the service life of an AMOLED panel.