Provided are a deicing unit adjustment mechanism, a deicing unit, a deicing vehicle, and a deicing method. The adjustment mechanism comprises sub-adjustment unit(s) comprising a positioning wheel, a screw rod, a guide rod having one end connected with the screw rod, an upper-end cover slidably arranged at one end of the screw rod away from the guide rod, a lower-end cover fixedly arranged at one end of the screw rod close to the guide rod, a positioning wheel-adjustment spring sleeved outside the screw rod and having two ends abutting against the upper- and lower-end covers and a pressure-adjusting nut at one end of the screw rod away from the guide rod and one side of the upper end cover away from the guide rod. The positioning wheel is rotatably-arranged at other end of the guide rod, with an axis of the positioning wheel perpendicular to that of the guide rod.