The present invention discloses a slit electrode for solving the problem that the process margin of the existing slit electrode is relatively low. The slit electrode provided by the present invention comprises: at least one slit electrode unit, the slit electrode unit comprising a plurality of strip electrodes, a slit being provided between two adjacent strip electrodes; wherein each strip electrode has a given average width, the average widths of at least two strip electrodes in the slit electrode unit are not equal. The present invention further discloses an array substrate comprising the slit electrode and a display device.