The invention provides a steel coil coiling machine coil core sleeve replacement method. By means of the method, a steel coil coiling machine coil core sleeve is replaced by using a safety stepping device. The safety stepping device is arranged above a deep pit beside a steel coil coiling machine coil core. The method comprises the following steps that 1, a worker gets into a stepping frame, openshandrails and inserts fixing pins for fixing the handrails; 2, the stepping frame is moved to the other side of the pit; when a pair of M-shaped roller bearings at the foremost end of the stepping frame leave a guide rail, the other M-shaped roller bearings support the stepping frame 8 to continue moving until the M-shaped roller bearings at the foremost end arrives at a guide rail on the other side; 3, the stepping frame stably moves on the guide rails to the working position below a coiling block, and a safety pin are inserted to fix the stepping frame; 4, a paper sleeve is handheld to conduct replacement; 5, the safety pin is pulled out, and the stepping frame is moved back; and 6, the handrails are folded, and the safety pin is inserted to store the stepping frame in the storage location.