Cleaner suction nozzle

The invention relates to a cleaner sucker provided with a pressure adjusting device preventing the pressure of water vapor generated by heating water raising exceedingly, which comprises a steam generating device supplying water vapor by heating water, suction pipelines positioned at one side of the steam generating device for guiding the air and foreign bodies flow from outside and a pressure adjusting device adjusting the pressure of the water vapor generated in the steam generating device. The pressure generating device comprises flowing parts moving along with the steam pressure in the steam generating device and elastic parts positioned at one side of the flowing parts for blocking the flowing parts to move. When the pressure in the sucker of the cleaner of the invention increases, part of the steam are discharged to exterior through the water inlet, so as to maintain the proper steam pressure in the sucker and prevent the sucker blasting and damaging due to the raise of the pressure as well as reduce ac