The invention discloses a motor train unit overhauling cleaner. The motor train unit overhauling cleaner comprises two rows of supporting bases which are arranged in a corresponding mode, wherein a side rail which corresponds to a rail is respectively arranged on the supporting bases at the two sides; a sliding cleaner which slides on the corresponding side rail is respectively arranged on the side rails at the two sides; a drive wheel driven by a first motor is arranged in each sliding cleaner; each drive wheel slides on the corresponding side rail; a supporting bracket is respectively arranged on the corresponding sliding cleaner; a cleaning rack which corresponds to a motor train unit is arranged on each supporting bracket; a cleaning frame which corresponds to the motor train unit is further arranged on each supporting bracket; a water tank is arranged on each sliding cleaner; water is pumped into a water tube by utilizing a water pump; and a cleaning plate capable of cleaning the motor train unit is arranged on the corresponding cleaning frame, so that water spraying can be carried out by utilizing water spray holes for flushing in a process of cleaning by use of the cleaning plate, and therefore, the cleaning quality can be improved while the cleaning efficiency is further improved.