The invention discloses an array substrate, a manufacturing method of the array substrate and a display device. The array substrate comprises a first pattern layer and a second pattern layer which are sequentially arranged on a substrate base plate. An organic insulating layer is arranged between the first pattern layer and the second pattern layer. The first pattern layer comprises a grid electrode of a thin film transistor, a grid line and data lines, wherein the grid electrode is connected with the grid line, the data lines are cut off through the grid line, and the data lines and the grid line are insulated and separated. The second pattern layer comprises a source electrode of the thin film transistor, a drain electrode of the thin film transistor and connection portions, wherein the source electrode is connected with the data lines, the data lines correspond to the connection portions respectively, and each connection portion is used for connecting the portions, located on the two sides of the grid line, of the corresponding data line. By means of the array substrate, the manufacturing method and the display device, the parasitic capacitance of the source electrode, the drain electrode and the grid electrode can be reduced, the overlap capacitance of the grid line and the data lines can be recued, and therefore the signal delay is reduced, the power consumption is lowered, and the residual image phenomenon can be eliminated.