A detecting method of a pixel circuit, a driving method of a display panel and a display device are provided. The pixel circuit includes a driving transistor, and the detecting method comprises: in a first charging cycle, applying a first data voltage to a gate electrode of the driving transistor, and in a first time duration, obtaining a first sensing voltage at a first electrode of the driving transistor and determining whether the first sensing voltage is equal to a first reference sensing voltage; and in a second charging cycle, applying a second data voltage to the gate electrode of the driving transistor, and in a second time duration, obtaining a second sensing voltage at the first electrode of the driving transistor and determining whether the second sensing voltage is equal to a second reference sensing voltage.