Abstract: To address the issue of production capacity succession in the transition from open-pit to un⁃ derground mining at Miaogou Iron Mine，a research on the transformation of the main shaft hoisting system is conducted. The diameter and width of the drum are determined to be 1 600 mm and 2.64 m，respectively. The transformation and installation methods for the head sheave platform，safety protection platform，and horizontal platform are studied，as well as the transformation methods for the unloading station pit，the seal⁃ ing of the electric locomotive repair chamber，and the drainage equipment at the -155 m level. On this ba⁃ sis，the transformation method for the main shaft tower is determined，and a tower stabilization method com⁃ bining composite reinforced piles with concrete curtain grouting is proposed，thus forming a comprehensive and integrated transformation technology for the main shaft hoisting system. The results of numerical simula⁃ tion show that significant settlement occurs on the southwest side of the main shaft tower，while the settle⁃ ment on the northeast side is relatively small，which verifies the reliability of the focused reinforcement us⁃ ing 5 composite reinforced piles on the southwest side of the tower. The maximum vertical displacement around the tower meets the requirement of less than 200 mm specified in the Code for Design of Building Foundation (GB 50007—2011)，which can effectively ensure the overall stability of the main shaft tower. The research results can provide guidance and reference for the transformation of main shaft hoisting systems in mines under similar conditions.

Key words: shaft, transformation of hoisting system, head sheave platform, tower stabilizationy, nu? merical simulation