An array substrate and a detecting circuit thereof are disclosed. The detecting circuit comprises a detecting unit, which comprises a first to a sixth detecting lines; a switching signal access unit, used for receiving a switching control signal; a detecting signal access unit, used for receiving a first detecting signal or a second detecting signal; and a switching unit, comprising a first switching line and a second switching line, which are connected among the detecting unit, the switching signal access unit and the detecting signal access unit. The array substrate comprises an active area and a detecting circuit.