The disclosure provides an array substrate, a display device, a detecting apparatus and a detecting method for detecting a defect connection of a data line. A data signal input bus of the array substrate of the present disclosure applies a data signal to each pixel unit, and a detection line is added on one side of the array substrate opposite to the data signal input bus, when the product is detected, the data signal input bus inputs the normal data signal, the detection line on the other side inputs a signal having a polarity contrary to that of the data signal. At a position of the data line existing defect connection, heat is generated and the data line is burnt at the position existing defect connection.