The invention relates to a large-diameter steel pipe semi-automatic brushing machine and a method for cleaning a mining large-diameter steel pipe through the machine. In order to fill up the space inthe prior art, the large-diameter steel pipe semi-automatic brushing machine comprises a long rack, a spindle box, a tail base box and a steel wire rope; two long sliding rails and a moving trolley are included, four guide wheels are arranged on the lower portion of the moving trolley, the moving trolley is provided with a stand column, the two ends of the steel wire rope are fixed to the stand column, a closed loop rope sleeve is formed, one end of the closed loop rope sleeve is arranged on an active steel wire rope winch spool in a sleeving manner, the other end of the closed loop ring sleeve is arranged on a passive pulley in a sleeving manner, the active steel wire rope winch pool is provided with a second driving motor, the top of the stand column is fixedly provided with a multi-layer combined hinge joint hoop brush, and multiple steel wire brushes are arranged on the inner side faces of an upper semicircle plate and a lower semicircle plate. Sewage on the steel pipe to be cleaned can be rapidly cleaned down, the steel pipe to be cleaned down is locally bent, cleaning is not affected, and the machine is widely suitable for outer wall cleaning work of underground large-diameter steel pipes.