A pixel circuit (1) and a driving method therefor, a display substrate, and a display device. The pixel circuit (1) comprises a driving circuit (10) and a compensation circuit (20). The compensation circuit (20) may connect an output end (OUT) to a second power end (VDD') under the control of a voltage signal of a control node (N) and the level of a second driving node (P2), so as to receive a second power signal. The pixel circuit (1) may input the second power signal to the output end (OUT) when a light-emitting element connected to the pixel circuit (1) fails to emit light normally, so as to enhance the luminance of a light-emitting element connected to the other pixel circuit or drive an alternative light-emitting element to emit light, thereby ensuring the display effect of the display device and improving the display quality of the display device.