The invention discloses a pixel circuit, a driving method of the pixel circuit, an organic light-emitting display panel and a display device. A unified public voltage signal is inputted to a first electrode of a drive transistor before a data signal is written into a control electrode of the drive transistor; the public voltage signal and a threshold voltage of the drive transistor are written into a control electrode of the drive transistor, so that relatively high current can pass through the drive transistor, threshold voltage deviation, which is caused by bias stress, of the drive transistor can be recovered, a retarding effect of the drive transistor can be improved and the occurrence of a ghosting phenomenon can be prevented; in addition, when the data signal is written into the control electrode of the drive transistor, a time of writing the data signal can be shortened, and the control electrode and the first electrode of the drive transistor can achieve jump through a unified potential, so that a difference, which is caused by stray capacitance between the control electrode and the first electrode of the drive transistor, can be prevented, the problem that threshold voltage grabbing is inconsistent due to voltage jump can be avoided and consistent brightness of the first frame after high-low grayscale switching can be guaranteed.