The invention relates to a down picker adjusting device for a hosiery machine and a method thereof, and belongs to the field of knitting machinery. The device comprises a down picker and an adjusting seat (4) for fixing the down picker, wherein the adjusting seat (4) is used for adjusting the position of the down picker front and back, up and down. The invention also relates to the down picker adjusting method for the hosiery machine. The method comprises the following steps of: gliding matching a down picker body (1) onto the adjusting seat (4) through a chute (13) on the adjusting seat (4);adjusting the front and back position of a press-needle rod (2) by adjusting an adjusting screw (7); and adjusting the upper and lower position of the press-needle rod (2) by adjusting an eccentric shaft (10). According to the device and the method of the invention, the adjusting seat for the down picker can be adjusted front and back, up and down in a certain range no matter how far the down picker is from a needle cylinder by adjusting the adjusting seat for the down picker of the hosiery machine front and back, up and down so as to find an optimal press-needle position of the press-needle rod.