Pixel circuit, driving method thereof and display device

The invention provides a pixel circuit. The pixel circuit includes a driving transistor and a light-emitting element which are connected in series between a first electric level end and a second electric level end, and as well a second transistor, a third transistor, a fourth transistor, a first capacitor and a second capacitor, wherein the second capacitor is connected between the control pole of the driving transistor and the second end of the light-emitting element. Threshold voltage is stored through the first capacitor, so that threshold voltage compensation of the driving transistor and the light-emitting element can be realized, and therefore, the nonuniformity of the display of the pixel circuit can be compensated. According to the above pixel circuit, the invention also provides a display device. According to the display device, a first control line and a light-emitting control line are both global lines. The invention further discloses a pixel circuit driving method.