A device to clean debris in a square-cover sewer belongs to the field of civil cleaning and is composed of a cylinder, a guide plate, an air pump, cross bars, a push bar, a controller, a turbine internal suction unit, a discharge pipe, a debris collection barrel, positioning bolts, four support legs, a cleaning component, castors, a guide pipe, a debris suction component, a battery and a base plate; the support legs are disposed at four corners of the base plate and are fixed via the positioning bolts; the cross bars are arranged on the two support legs on the left side; the push bar is arranged between the two cross bars; the cylinder is mounted in the middle of the base plate; the air pump is arranged on the left of the air cylinder; the battery and the turbine internal suction unit arearranged on the right of the air cylinder; the discharge end of the turbine internal suction unit is provided with the discharge pipe. The device is capable of all-directionally cleaning debris in thesquare-cover sewer, and the height of the base plate herein is adaptively adjustable.