A detection circuit of a display panel and a detection method thereof are disclosed. The detection circuit includes two detection lines respectively for providing scan signals for each row of pixel units. One of the detection lines is only connected to one scan line of the pixel unit and the other one of the detection lines is connected to another scan line of the pixel unit. By way of connecting two scan lines of the pixel unit to different detection lines and applying different voltages respectively thereto, the present invention can detect abnormalities of the display panel.