A display device and a manufacturing method thereof are provided. The display device includes a display panel and a flexible circuit board electrically connected with the display panel. The flexible circuit board includes a first circuit board, a second circuit board and a conductive portion; the first circuit board includes a first substrate, and a main contact pad, a first wire and a second wire provided on the first substrate; the second circuit board includes a second substrate, a relay contact pad and a third wire provided on the second substrate; and the conductive portion is configured for electrically connecting the main contact pad and the relay contact pad.