The present disclosure provides a display device and a detection method for the display device. The display device includes a display area and a non-display area. The display device comprises: a pixel array at the display area, a plurality of switching transistors at the non-display area, and at least one detection line at the non-display area. The pixel array includes a plurality of sub-pixels. The plurality of switching transistors are electrically connected to a plurality of columns of sub-pixels of the pixel array in one-to-one correspondence. Each of the at least one detection line is electrically connected to a part of the plurality of switching transistors.