The invention discloses a process method of a signal line of a display panel and the display panel. The method comprises the steps as follows: a material layer of the signal line is formed on the display panel; a photoresist layer is formed on the material layer; photomask treatment is carried out on the photoresist layer with a mask, so that the photoresist layer forms a stepped pattern; the stepped patterned photoresist layer comprises a first type of exposed region and a second type of exposed region; the height of the first type of exposed region is different from that of the second type of exposed region; the first type of exposed region of the stepped patterned photoresist layer is removed while the second type of exposed region is reserved; and the material layer is etched employing the second type of exposed region of the residual photoresist layer as the mask, so as to obtain the patterned material layer on the display panel. In the manner, the signal line with a relatively small line width can be obtained.