The invention discloses a steel structure drilling device convenient to use. The steel structure drilling device comprises a bottom plate, the left side and the right side of the top of the bottom plate are both fixedly connected with supporting plates, the tops of the two supporting plates are fixedly connected through a top plate, the top of the top plate is fixedly connected with an air cylinder, and the bottom end of the air cylinder penetrates through the top plate and extends to the exterior of the top plate. According to the steel structure drilling device convenient to use, through mutual cooperation of the air cylinder, a drilling motor, a drilling rotating shaft, a first gear, a second gear, a rotating shaft, a second bearing, a drill bit, a threaded block, an adjusting motor, anadjusting rotating shaft, a third bearing, a third gear, a fourth gear, a threaded rotating shaft, a fourth bearing, a horizontal-moving motor and a strip-shaped gear groove, the problem of inconvenient use of a common steel structure drilling device is solved, when a plurality of drilled holes are formed in a steel structure, an automatic adjustment mode is adopted, the drilling position is convenient to adjust, the labor intensity of workers is lowered, the drilling error is reduced, and great convenience is brought to drilling work.