An array substrate, a fault line repair method thereof, and a display device are provided. The array substrate includes: a base substrate; a gate line and a signal line which are arranged on the base substrate, adjacent gate lines and adjacent signal lines crossing with each other to define a pixel region; and a pixel electrode located in the pixel region. The array substrate further includes a common electrode corresponding to the pixel electrode. The common electrode includes: a frame; a first strip-shaped connection part arranged in the frame and having both ends thereof connected with the frame; and a second strip-shaped connection part connected with the first strip-shaped connection part in a crossed manner and having both ends thereof disconnected from the frame. The signal line is parallel with the second strip-shaped connection part and located directly above or directly under the second strip-shaped connection part.